Many credit cards like Diner's Club, Amex Platinum, or Visa Black have their own programs.
For example, Amex Platinum gives you priority pass select + AA Admiral Clubs + US Airways Clubs + Delta SkyClubs. You need to be flying on those airlines to use those lounges (except for US Airways). Priority pass is going to have a big devaluation at the end of this month when they lose the Continental/United lounges.