During last 10 month I have credited AY 95 segments to AA. This includes flybe-operated 3XXX segments with AY, AY segments in deep discount etc.

Everything credits (automatically) as Y, usually at least 1 week after the flight on monday. NO hassle at all. I do the online checking to make sure that correct FF number is on the boarding pass. Claiming also works without any problems with AA.

Only problem I had was in last year when ZRH clerk was able to input my AA FF number with AY prefix. This ended into infite loop between AY and AA both claiming that I got the miles thru other program, and I never got the miles. I eventually did MR to recover the missing 950 miles to get the AA plat.

I have yet to take any 8XXX flights, but since I have had no consistent problems with any AY ticketed flights being credited to AA, I presume they will work the same way as flybe operated AY 3XXX flights.