American Airlines and GOL announced back in February (read more here) that they were in the process of launching (again) codeshare and frequent flier agreements.
AAdvantage and Smiles members can now earn and redeem miles on each other’s flights effective May 7, 2020.
Here’s AAdvantage page for GOL earnings:
GOL Smiles earnings for American Airlines:
You can also redeem Smiles for AA online:
GOL used to be a partner with Delta (when TAM was part of Star Alliance) and LATAM with American (within Oneworld). Delta bought a stake in LATAM last year (read more here) that resulted in the airline’s prompt exit from the Oneworld that took place on May 1.
GOL and American Airlines then decided to partner again (they used to be in the early 2000s), and this earning and redeeming miles is now in effect.
It seems, however, that you need to call AAdvantage if you want to redeem them for GOL flights. You can already use Smiles for American flights online.
I would not, however, credit any flights to Smiles as you can buy their miles cheaply during frequent sales, and the number of miles required for non-GOL flights is ridiculous.