My understanding is that QF -
1. Will interline bags to another airline on the same PNR (assuming they have an interline agreement)
2. Will interline bags to another oneworld airline on a separate PNR
3, Will not interline bags to a non-oneworld airline on a separate PNR.

You may get lucky but I would seriously doubt they will interline to AS on a separate PNR. In any event, you will have to collect your bags and clear customs at LAX so not sure the interlining buys you much. At best, just persuade them to at least tag the bag to YVR so you don't have to get it tagged in LAX - you'll still have to collect the bag and 'interline' it yourself in LAX. I don't understand the "extra bag" issue - are you saying that you can take 2 bags internationally but only 1 on the AS flight, so that if they interline you could get 2 bags on the AS flight? Either you need 2 bags or you don't - I don't see the point of taking an extra bag just because you can.