Bangkok Airways and Cathay Pacific frequent flier program members have been able to earn and redeem on each others flights from June 1, 2015.
The Bangkok Airways FlyerBonus earning and burning rates on Cathay Pacific flights are terrible. Cathay Pacific AsiaMiles is far more reasonable.
Hong Kong To Los Angeles:
Hong Kong to Los Angeles would earn 135 credits while redeeming for first class on the same sector requires 4,400 credits.
It is always good to have more partner to earn and burn miles/points. Bangkok Airways FlyerBonus members are far better when crediting these flights to other frequent flier programs such as American Airlines AAdvantage.