It's hard to beat Casa Mono and Bar Jamon for having the most robust Spanish wine list in the country today. In terms of wines list, they can even go toe-to-toe with some of the regarded restaurants in Spain that I've been in.
A (very, very) distant second in NYC, imho, might be Boqueria, La Solera and La Fonda del Sol.
52 Irving Place, New York, NY 10003
125 E 17th St, New York, NY 10003