AS THE automatic machines applied the last of the 1979 labels on wine bottles throughout Bordeaux this summer, a widespread consensus was emerging that it, indeed, had happened again. The "pair phenomenon" still lives.

Since 1959, every "great" vintage in Bordeaux (1961, 1966, 1970, 1975, 1978) has been followed by a vintage that, although not uniformly as outstanding as its immediate predecessor, has been very good and noticeably cheaper. In some instances, the latter-year wines actually have been better than their older brothers in certain areas of Bordeaux -- usually in Pomerol, St. Emilion and the southern Medoc -- where the grapes mature somewhat earlier (1967, 1971).

The quality of the 1979 clarets not only perpetuates the "pair phenomenon," but the high quantity of the vintage should provide American consumers some welcome alternatives to the very expensive 1978 clarets. The largest harvest in the postwar years, coupled with a strong American dollar, may result in prices for 1979 clarets -- most of which will arrive in the United States next spring -- some 10 to 25 percent below those for the corresponding 1978 wines. Even if additional markups are taken this winter -- in response to the slow-selling, mediocre-to-poor 1980s or to initial prospects for the 1981 vintage -- the 1979s may be the best premium wine value available in today's market. Indeed, top-flight California producers may be obliged to temper their escalating pricing policies.

The precise evaluation of young, recently bottled wine is a tentative undertaking at best, and clarets from the same vintage can vary widely throughout the Gironde. Nevertheless a series of six tastings in Bordeaux this summer, from Pauillac to Pomerol, confirmed earlier evidence that the 1979s are not only good values but are fruity, harmonious, generally forward wines which are more firmly structured than the 1976 or 1967 clarets. To Alexis Lichine, they are reminiscent of the 1962s -- and at this point noticeably cheaper.

Of 41 wines sampled over a three-day period in July, the clear superstars were Chateau Mouton-Rothschild, Chateau Palmer, Chateau Haut Brion and Chateau Leoville-Las Cases (see individual notes elsewhere). Although not tasted for this review, Chateau Margaux is also widely acclaimed.

Christian Moieux, whose family owns Chateau Petrus, Chateau Trotanoy and numerous other properties on the "right bank" of the Gironde, is among the many proprietors who believe that the 1979 wines from Pomerol and St. Emilion are superior to their 1978s. At a comparative tasting of seven wines from Pomerol and St. Emilion at his company's cellars in Libourne, the 1979s indeed displayed noticeably more fruit and better balance than the corresponding 1978s. The differences were more pronounced with the three St. Emilion wines than those from Pomerol. But because the fleshy, forward 1979s would naturally appear to be more attractive at this early stage than the more tannic 1978s, any "quality" differences between the two may ultimately depend more on personal preference than enological fact.

Jean Eugene Borie, the energetic proprietor at Chateau Ducru Beaucaillou, prefers the 1979 Haut Batailley over that chateau's 1978, but he adds that such exceptions are rarer in the Medoc than across the river. His 1979 Ducru is good but not really in the same league as his exceptional 1978. The 1979 harvest, which began Oct. 9, was the latest of this century and, even though unusually sunny weather continued for several weeks thereafter, some growers (with long memories of the vagaries of past October weather) picked cabernet sauvignon at sugar levels that were less than optimum.

Selectivity has been sound advice in the past when considering wines from the latter year of paired vintages. That would appear to be particularly true in the case of the 1979s. Quantity seldom begets quality (1970 being a notable exception). Those chateaux -- particularly in the Medoc, where the later-maturing cabernet sauvignon is the principal grape variety -- that chose only their better lots (selling their substandard wine to be bottled under lesser labels) will have produced the best 1979 claret. Thus it comes as no surprise that some of the best 1979 wine in Bordeaux comes from those few dozen producers whose selectivity and careful vinification have established them throughout recent decades as consistently in the top flights.

All things considered, the 1979 clarets are well timed. Evidence is slowly mounting of growing consumer resistance in America to $20-a-bottle prices for the classified growths. The franc has lost nearly 30 percent of its value in the past 12 months. The 1980 vintage has proven hard to sell at any price. The new Socialist government in Paris has made owners and negotiants alike particularly nervous about the future.

In such times, the Bordelaise could use some reassurance.