How important is it to buy a bottle of wine from a vintage year? How sure a guarantee of qualify is the name of a famous chateau or vineyard on the bottle? During the wave of excitement that sent wine sales soaring in this country during the late 1960s a message was imprinted on the collective brain of the wine-buying public: From France buy only vintage years and buy only chateau wines.

The result has been, some wine experts believe, a distortion of tradition. They argue that the grand chateaux have swollowed their pride and bottled wine in years of marginal quality, that undistinguished wine armed with the name of an insignificant property and a vintage tag has been foised on a too-willing public; that at whatever price wines in both these categories are overpriced.

Turning the coin over, they argue that the public has been denied access to a type of wine that once was of considerable importance in both the Bordeaux and Burgundy trade - blended regional or commune wines. Blending, Eduoard Kressman wrote in his underappreciated book, "The Wonder World of Wine," is the essence of the winemacker's art. Yet the emphasis on vintage and on estate wines, he complained, hadall but eliminated demand for shippers' blends, Furthermore, the rush to bottle under a chateau name meant some of the wine best suited to enhance blends was no longer available in bulk to the shipper.

Alfio Moriconi, who imports blended wines for Wines Limited of Silver Spring from a French firm called French Wine Farmers, issued a challenge: He felt the blended wines could more than hold their own against fancy wines from the same regions. So a blind tasting was arranged. The vintage wines were from the generally mediocre years of 1972, '73 and '74, but came from prestige shippers or chateaux.

French Wine Farmers entries came in first in three white and two red wine categories. The most popular wine of the tasting was their blended red from a secondary Bordeaux area, the Cote de Bourg. It sells for $2.99. Red Mouton Cadet, a blended vintage wine, made much less of an impression. It sells for $3.69.

"Blended wines can be fine," one of the tasters observed. "But you must find a shipper who is reliable and how do you do that?" "It's no harder than finding the right mechanic for your car," someone answered. All too often it isn't any easier, either.

Dr. Albert Burklin, one of Germany's leading winemakers, visited the city recently to publicize the highly regarded wines he produces in the Rhinepfaiz region. Less well known than the Rhinegau or Mosel, the Rhinepfalz often outproduces them both. But most of the wine - both red and white - is, according to the late Frank Schoomaker, "very common." However, the best, he wrote, are rieslings that are "fine, fuller bodied than the Rhinegaus but hardly inferior to them. They have considerable bouquet and breed and go better than most other German wines with food."

Offered for tasting at a luncheon, were two 1975 riesling kabinett, Ruppertsberger Reiterpfad and Wachenheimer Rechbachel : two riesling spatlese, Forster Ungeheuer 1975 and Deidesheimer Langenmorgen 1973, and two 1971 riesling auslese, Forster Ungeheuer and Wachenheimer Goldbachel . All are from the Weingut Dr. Burklin-Wolf.

Burklin proved himself a man of restraint. Asked about the 1976 vintage in Germany, currently the subject of lavish praise, he answered: "The wine is very good. On the other hand it's not rue it is such outstanding wine." To him, the 1976s are slightly superior to the "very nice" wines of 1975. "It (1976) will be a pearl," he said, but not a jewel. "It was too dry during the summer and then during the harvest it started to rain at the wrong time."

Lovers of German wine should not dispair, however. To him, 1971 and 1959 were mere pearls as well. His last "jewel" ranking went to the 1945 vintage.

Kenneth Onish, vice president of Chateau & Estate Wines, the U.S. firm that imports Burklin-Wolf Wines, had some interesting observations on the market distortions that may be caused by the unusual 1976 harvest. A great deal of the wine from a vintage of limited quantity is spatlese or higher so that there is going to be a shortage of wines at prices under $4. Meanwhile the prices on top qualify wines are going to jump. Estimates range from 30 to more than 60 per cent.

Onish said his firm has "absorbed" some of the markup, trying to keep prices from pyramiding further along the supply pipeline. "We realize there is a difficult marketing problem," he said. "I've advised producers who don't have cash flow problems to put their '76 wines away for a while. Maybe we will get back to normal with the '77s, but it's important the healthy sales momentum we have from the '75s be continued."

Even though the German wines are white and often fresh tasting, he counseled patience when buying for quality. "Fine riesling needs six months to a year in wood," he said. "I don't think we'll ship our '76s before Sept. 1 or even the end of the year. The wines that arrive before the summer are light and won't improve." In contrast to the majority opinion that '76s has outdone '75s in all respects, Onish perfers the Mosels of 1975 to those of '76. "The '76s lack acidity," he said, "especially those from the middle Mosel.People who love their wine sweet will love the '76s, but I think the '76s have better balance.

He said Washington ranked only behind the San Francisco and the ski resorts of Colorado as a market for German estate wines. New York City, he said, is a French wine town though California chardonnay has been making headway.

Onish, who had worked for Frank Schoonmaker before the famed importer's death, reported the Schoonmaker stable of growers in France and Germany was still intact and that since Schoonmaker Selections became part of Seagram's Chateau and Estate Wines the line has not been expanded or otherwise subjected to pressures of crass commercialism.