I would advise against AC:
- huge copay on most carriers
- $90 change fees and $30 booking fees
- limited and overpriced one-ways
- weak online booking engine
- only 125% earn on business fares

AC program's main strength is (ummm, was) generous upgrades from lowest economy fares, but only on its own metal. For purely earning and burning miles they are mediocre at best. I'd try Avianca or stay with A3.