S -- O -- N -- O -- M -- A! S -- O -- N -- O -- M -- A!Only a uniformed squad of cheerleaders was missing when representatives of 23 wineries from California's Sonoma County hit town last week, and they weren't needed. In two days of almost nonstop tasting and talking, the winemakers and vineyard owners performed impressively before audiences of retailers and restaurateurs. So did their wines.

The general quality level was high, much higher than it would have been only a few years ago. That, in a sense, was what the 1970s were all about for California winemakers: using experience and technology to improve their products to the point where, as one of them put it during a tasting at the Capitol Hill Club, "these are world class wines."

The tasting had a second purpose, however. The wine people came here (and to Boston and New York on the same barnstorming tour) to beat the drum for Sonoma as a region and to provide increased visability for themselves as well as their products. Having proven themselves capable of making excellent wines during the past decade, it seems clear that their great challenge for the '80s is one of marketing.

Sonoma County has dwelled in the shadow of Napa, its neighbor to the east, ever since Prohibition ended. Sonoma has some famous names: Buena Vista, Hanzell and, more recently, Sebastiani. But for years most Sonoma grapes were shipped elsewhere and only since the mid-1960s have wineries begun to proliferate. There are now at least 35 members of the Sonoma County Wine Growers Association and others outside the group.

"We're here for two reasons," said Franks Woods of Clos du Bois. "Much of the restaurant and retail trade on the East Coast is thought to have a bias toward European wines. We hope to convince these people that our wines have equal merit. For those who are into California wines, we want to make a strong impression of Sonoma as a distinct region."

"It's a bit like Avis," added Rod Strong of Sonoma Vineyards. "We have to try a little harder to make the country aware that the term 'fine premium wine' isn't synonymous with Napa."

Part of their pitch was to show the diversity of the region, which begins about 40 miles north of San Francisco and runs north and south for nearly 100 miles, separated from the ocean to the west by costal mountains and from the Napa Valley by a range of hills.

There was diversity of size, too. Geyser Peak, Souverain and Sonoma Vineyards are among the country's largest producers.Foppiano, Pedroncelli and the revived Buena Vista are in the 100,000-case middle range.

There would be considerable competition for the smallest. Landmark, Davis Bynum, Grand Cru, Hacienda and Mark West all have reputations that far exceed their production.

Until recently, most promotion was done by giant wineries with broad national distribution. What led to the change is that the rush to winemaking in the past two decades has filled the carafe of California to overflowing. There is too much wine, and too many wineries, to fit comfortably on store shelves or restaurant wine lists. With more wineries arriving on the scene (there are now more than 400 in California and wine is being produced in more than 30 other states), a growing number of smaller California wineries have tried to hedge their bets and sell at least part of their production outside the state.

During the past three or four years, circumstances have favored "exportation" eastward. Prices for imported wines, particularly those from France, shot up sharply in the face of double-digit inflation and the declining value of the dollar. Previously closed-minded restaurateurs and retailers were willing to listen and taste, and so were value-conscious consumers.

Recently, however, there has been a change of circumstances. California wines -- even gold medal winners -- no longer are curiosities here. Individual wineries need to develop name recognition; something done with great success, for example, by Robert Mondavi of Napa.

Also, the cost of California wines has gone up rather sharply and none of the winemakers here last week foresaw a downturn. Moderately priced Italy has been a beneficiary in the quality wine sales competition, and now there are reports that the retail prices of some French wines may be dropping soon. This represents another challenge. Have the Californians established a solid beachhead, or, without a price advantage, will they lose Eastern consumers to the lure of French labels in head to head competition?

Of course the winemakes have some options. Those who own vineyards can contain costs somewhat by increasing the yield-per-acre. This would give them more wine, but, as one put it, would "give us a watered-down version of what we want to make." A more viable alternative for the quality-conscious producer is to make wines that are ready to drink when they arrive at a retail store or restaurant, or to hold back wines -- particularly reds -- until they are mature.

The "safe" situation these days, most observers agree, is to be of at least moderate size (25,000 or 30,000 cases), out of the "high end" of the price structure and with a production ratio of more white wine than red. There is talk of "shakeouts" (of wineries going broke and closing), especially those with very limited production or with young vines on very expensive acrage. Nonetheless, representatives of some of the smaller wineries were among the most exuberant.

"Isn't everything in life a gamble?" asked Joan Ellis of Mark West. The winery made 8,000 cases last year, divided among five wines. The Ellis' vineyard was purchased in 1972 and planted in 1974, so they have the advantage of relatively low overhead and mature vines. They plan to grow slowly toward 25,000 cases and sell in the "high-middle" price range. "Why are we here?" Mrs. Ellis said. "There isn't any more shelf space left and who's ever heard of Mark West? We need name identity and luckily we can get free to travel around."

Iron Horse, one of the newest wineries, won't release its first cabernet or pinot noir for more than a year. They, too, are aiming for a production of 22,000 to 24,000 cases, all from their own vineyards. According to owner Audrey Stirling, about 25 percent of the production will be shipped east. Winemaker Forrest Tanser is dedicated to making French-style chardonnay and pinot noir, "wines of finesse and character, not wines that you can stand up a spoon in." They rank consistency of supply as a high priority, something that has been a problem heretofore for shops and restaurants that buy from small California producers. "The acid test (of our dedication) will come," Tanner said, "if we are very successful and are able to resist demands for new business."

Steve MacRostie, the winemaker and a partner in Hacienda Wine Cellars, summed up the attitude of the smaller wineries best. "Sure, it's becoming very competitive," he said. "What was an exceptional wine a few years ago now has some company. That's how good we've gotten. Prices are up, but I think we are doing very well offering dollar-for-dollar value against any wine in the world. We intend to stay very small, to make a good product and make a good living at it. I'm sure we can."

Rating wines in the midst of a stand-up tasting with nearly 50 wines being poured is unwise if not impossible. In any less-than-comprehensive tasting several wines did stand out, however. They included a 1974 chenin blanc of Alexander Valley Vineyards, 1979 dry gewurztraminer from Chateau St. Jean, a superb 1977 pinot noir from Davis Bynum, Foppiano's 1976 petite sirah, Gundlach Bundschu's 1978 gewurztraminer, Hacienda's 1977 cabernet and 1978 "Clair de Lune" chardonnay, Kenwood's 1977 Jack London cabernet, Landmark's 1978 chardonnay, an exceptional 1978 gewurztraminer from Mark West and a superior one from Pedroncelli, Sonoma Vineyard's 1978 Chalk Hill chardonnay and the intense 1976 zinfandel from Trentadue.