Actualy, I usualy use my card for American Airlines tickets and get billed in Mexican Pesos for them at the exchange rate and save that 2%. As I lived in Europe this last year but plan to return to Mexico to work, I will start using it a lot. In Europe I use another kind of card (european) and is not the Citibank AAdvantage. I also have an american credit card to use while in the USA, but it is a cash back no anual fee.

To answer your question, yes, you are subject to that extra charges when using it outside Mexico.