The free bag benefit has always been for domestic itineraries only. "Domestic" for this purpose includes the continental United States, Hawaii, Alaska, Puerto Rico, the U.S. Virgin Islands, and Canada.

The big change is that AA started charging for the first checked bag to many Caribbean destinations for tickets issued on or after April 8, 2014. Before then, the first bag to Curacao was free regardless of whether or not you had the credit card. The credit card benefits never changed; rather, the baggage policy did.

I've heard reports that cardholders were able to get their first bag fee waived on Mexican/Central American/Caribbean itineraries, but these were one-off mistakes by agents confused about the card benefits rather than any official policy. Now that the AA/US merger is complete (from the passenger's point of view) and everyone is on the same page, these occurrences should see a sharp reduction.