My wife and I stopped in at Wine on Piedmont while we exploring Oakland yesterday. It's a great neighborhood wine store, and might be worth a special trip if you're looking for unusual wines or cocktail ingredients.
Some of the highlights included harder-to-find cocktail ingredients like Creme de Violette, Cocchi Americano, white and red Lillet, and a good variety of vermouths. They had a bunch of different bitters on the bottom shelf, and an interesting collection of gin. I didn't spend a huge amount of time looking at their wine, but a few finds jumped out at me like Txakoli (a lightly sparkling Basque white wine) and Braquetto d'Aqui (which I've never had before but is billed as a red wine version of Moscato d'Asti).
The owner was very friendly and knowledgeable. I'm definitely looking forward to returning next time I'm in Oakland.