I booked a reward ticket from ba.com, received an email from British Airways with ticket number and booking reference number. The flight is an American Airline flight. I want to select my seat from aa.com. However, aa.com cannot find my reservation. It seems the booking reference number is not an AA Record locator. The ticket number starts with 125, which cannot be searched in aa.com. I wonder how I could do online check-in if aa.com cannot find my ticket?

Another question, I booked the reward ticket from household account, do all people in the household account satisfy redeem activity (miles don't expire in 36 months)?