Well, if you're flying full fare Y, you could easily do a Platinum Challenge on AA, make Plat and therefore get lounge access on international trips, and at Oneworld partners' lounges overseas, and as AA Plat get upgraded on domestic and Canada/Caribbean/Mexico/Central America flights on any full-fare (Y/B) economy ticket. You'd also get "sticker" 500-mile upgrades (4 per 10K BIS miles) good on any domestic discount Y fare, no bag fees, priority access at the counters, and various other perks. AA supposedly requires 4 AA-metal flights annually to requalify, but it seems nobody has ever lost status by not doing the four flights.

To keep Plat status you need to log 50K EQ Points or EQ Miles in a calendar year; however Y and B economy earns 1.5 EQP per flown mile, so you'd retain Plat with 33,333 flown miles in those fares (or any business/first). In redemption terms, AA is about as good as it gets, and if you're spending more time in Latin America, AA's route structure is also the best.