I don't believe bars/clubs are good place for Aspies to meet people.
Probably the best way, within a bar/pub at least, is to play trivia games and do well at them.
Or watch a sporting event in a bar/pub, and be a fan of the team which most of the patrons are fans of. You can make friends that way, and perhaps even talk to a woman that way.
If you want to talk to a woman, MAKE SURE SHE'S NOT WITH SOMEONE ELSE! Guys who are drunk and feel like some guy is intruding on "his woman" will get very angry and might try to start a fight.
In general, especially in clubs rather than bars, I find the music to be too loud to communicate with others.