I've had troubles with this. I am OWE with QF but and close to Lifetime Gold so am crediting my OPT - PHX run to BA (only Blue). Entered my BA number in AA.com and want to add my QF number to the BA PNR (free seat selection as well as 1A on the 747). Just won't accept it! Even the F ticketing desk at T5 couldn't do it. Very strange.