LoyaltyLobby
American Airlines seems to be in “love” with alliances; one on the West Coast with Alaska Airlines (becoming Oneworld Alliance member on March 31), and another one for the East Coast with JetBlue.
American Airlines previously had a partnership with JetBlue that ended on April 1, 2014 (read more here), and the new one was announced on July 2020 (read more here), although the start date was left in the dark.
You can access AA’s page for the alliance here and JetBlue’s here.
American Airlines and JetBlue will start codesharing select flights from February 25, 2021.
The loyalty benefits are not yet in place, however: