Flight posted - no tier points. 25% miles for B/H class. There is a difference in the booking codes that qualify for full fare economy between AA and AS - AA includes Y,B,H and AS includes only Y, B.
I need to go back and check my itin because I thought I had B but maybe it was H. At any rate, even though it was an AA flight number the posting was for an AS flight number. So it seems that the AA codeshare aspect is irrelevant in how the flight posts with BA.