My mum and her SO are switching FF program after reaching lifetime top tier on SQ (and extremely disenchanted by it). They're flying P class SIN-HKG-LHR r/t on CX next week. What's the best program to earn bonuses (any on right now other than the N.America-HKG one) with for CX premium travel as well as redemption? I imagine it isn't BA worldwide. Asiamiles? AAdvantage? Any suggestions?