Flying on CX J, QFF or Asia miles ?

[FL360]

Hello all,

you probably can answer me within 1 second for this question, I will be flying SYD->HKG->LHR and return on CX J soon,
I have been accumulating points on QFF because of credit card spend etc etc, but for flying mostly on other airlines.

Should I join asiamiles or credit this to QFF ? my aim for the frequent flyer program is to redeem international flights.

thanks heaps.