You can earn AA miles flying MA but not redeem awards on MA yet -- that won't happen until full OW membership. This thread was about flying and earning miles so I kept it brief, but apparently too brief for some.
Edited to add that the partners page has been updated and MA has been removed ... it was there earlier in June (and supposedly started earning miles as of June 1). So either the page update is a mistake, or MA isn't earning Aadvantage miles yet. Not a good omen, this was the first sign of LX having trouble with joining OW, when BA blackballed it. This time BA won't do that, as BAA owns the airport in Hungary where MA is hubbed and has a bit of influence over BA which it would use to protect its investment.