French and Spanish champagne houses have forged alliances with local winemakers, again taking advantage of the first-rate pinot and chardonnay grapes they use to make sparkling wines. Taittinger has built an impressive French-style chateau to house its Carneros winery named Domaine Carneros. A rose-lined driveway leads to a classical structure with a huge balcony looking over the vineyards. In the elegant tasting room is served their Carneros-produced sparkling wine. Events: All Carneros wineries participate in festivals held in April and November. Holiday in Carneros will be Nov. 19-20. Wineries will hold open house and offer holiday foods and gifts, including vine wreaths. The April in Carneros celebration will be April 22-23, 1995, with wineries offering new releases from previous vintages and special vineyard tours. Fields of wild mustard will be in bloom. Carneros Quality Alliance TASTEFUL: Neat rows of grapevines stripe the fields, above, at Domaine Carneros winery. Right, member winemakers of the Carneros Quality Alliance salute their patrons. The rolling hills of the Carneros region are about an hour north of San Francisco. QUIET MOMENT: Vineyards provide the scenery along California 121, the Carneros Highway.