From the Land Of the Proletariat, A Hedonist's Drink
LEAD: ONE of the more curious enclaves in this Black Sea port is a turn-of-the-century French chateau, its garden now festooned with Communist Party posters and heaped with industrial racks of empty green bottles. A voluptuous stone siren presides over the arched entrance, and high above her is the oddly proletarian sign, Factory of Champagne
