Citi temporarily added the American Airlines AAdvantage program as a transfer partner in 2021, but transferring your ThankYou points to this program is no longer possible. However, if you transfer your ThankYou points to a oneworld alliance member, such as British Airways, Qantas or Qatar Airways, using the transferred points to book an American Airlines flight is an option. Transferring your points to Etihad Guest and then using them for American Airlines flights is also possible.