The oneworld page for AA lists American Eagle as their only affiliate airline; I think that term means something else.
I believe that JL and QF are the two exceptions on which the operating carrier does not have to be a oneworld carrier. However, given AA's lack of a statement on which operating carriers are acceptable, it's kind of a "whatever AA decides goes" situation.
I did notice when booking this fare that you could also buy the JL codeshare from JFK to SAN on B6. I would have hopped on that except it would only book in Y even though the flight had Mint. It would be a crazy world, earning AA miles while flying JetBlue Mint...