Seat Assignment
 

I booked a trip using miles LAX-SFO-LHR-PRG. I booked through AA but the flights are booked on BA. The first leg, LAX to SFO is the leg that has me slightly confused. ON AA it says "You are traveling on a carrier other than American Airlines or American Eagle; please call BRITISH AIRWAYS for your seat assignment." But on BA it says that I can't choose seats on BA's site I have to do it through AA. The flight is AA 6047 operated by Compass Airlines. I was able to choose seats and they show on AA but not on BA.

Should I be worried?

I wouldn't think so. Worst case the seat assignment is not legit and you are stuck in a less than ideal seat for a 45-60 minute flight. Just check in at the 24 hour mark and select (or re-select) your seat then.

LAX-SFO is on AA metal, no problem in selecting seat assignments as this is an AA award booked on AA. BA will have nothing to do with this, and the seat assigment will not show on BA. I pressume the transatlantic portion to LHR is through BA, this is where you select seat through BA. You are fine.

Ask AA for the BA PNR. Then you can select seats at BA.Com for the BA Operated flights. If you don't have status, you have to pay for it.

I have that and BA says I have to book it through AA.

I'm in a loop. We'll see what happens when I check in.

If you have OW Sapphire or Emerald elite status, you can reserve seats online @BA in advance. If you have Ruby or no status, you can still book online, but only 24 hours before departure.
Try to do this rather than waiting until checkin.

AA booked my seat assignment on BA for me on an award flight. Then it disappeared on aa.com so I called BA and they said I already had the seat I requested. This was done at the Mexican AA reservation 800 number. AA should be able to do it anywhere else.