Despite its status as one of the world’s great wine capitals — the Bordelais would say their city is the great wine capital — wine bars have only recently become popular in Bordeaux. Happily, now it’s possible to sample some really excellent wines by the glass at a number of stylish and hospitable places. Perhaps the most eagerly awaited debut of the year will be at the dramatically designed La Cité du Vin, a multimedia exposition center devoted to the history, geography, geology and art of wine that is scheduled to open in June.