Originally Posted by
Happy
You dont need to fly from LAX. AS would transport you on AS flight between LAX-SFO, or between LAX-YVR - you can fly to HKG from SFO or YVR. I dont know if AS would let you fly LAX-JFK-HKG, which is a valid routing for CX, and bookable using AA miles. Dont know if AS allows such though. CX also flies to Hong Kong from YYZ and ORD.
AS does NOT fly LAX-SFO any longer (eliminated that route some years ago). They
do fly LAX-SJC, and I can personally attest that they will consider SJC/OAK/SFO as coterminals for CX awards (but that still means you have to get from SJC or OAK to SFO, or vice versa).
AS also does NOT allow mixed partners on awards*, so you can't have AA and CX on the same award (so AA can't fly you to ORD or YYZ from LAX to connect to CX on an AS award)- the only airline you can use to get to a partner gateway is AS. They also don't allow backtracking, generally, which probably means an itinerary of LAX-SEA-ORD(AS)-HKG(CX) isn't going to be allowed on one award (AS does not fly to YYZ, and I don't think they allow XXX-SEA-EWR//JFK-HKG routings).
* one exception: AF/KL are considered as if they are one partner for awards.