Sorry for the really noob-ish question, as I am new around here.
I have a DUS-LHR-PEK RT flight coming up on BA First (Fare Class A). I am currently a CX Silver (OneWorld Ruby) (till May 2016) and my main base is in HK/China. I considered crediting this flight to CX, but it seems that it wont get me any higher. Instead I was considering crediting this to BA, earning me 500 TP, which is enough to get me BA Silver (OneWorld Sapphire) after my next flight from PEK-LHR on CX.
However, I also looked at AA's Plat Challenge and it seems that my flights would also qualify me for AA Plat. Which one is better for someone based in China/HKG? Thanks!
PS: Sorry for the bad English, it is not my first language!