For OW flights to Europe, no reason the OP even has to go to HKG. BA and AY can both be found at BKK/SIN for flights to Europe. RJ also has a daily to BKK and 3x weekly to KUL with many connections into Europe from AMM. Connections from PEN are very short to any of SIN/KUL/BKK.

Only benefit I can really see is that CZ has pretty cheap (comparatively) Z fares D fares if you want to ride in Business. Otherwise the earnings rates for CI/CZ/MU on Skyteam are dismal for the majority of commonly found fares on booking sites. You are usually looking at 40% earnings in SkyPearl or 25% earnings in FB. In your situation, unless you will do a lot of domestic China flights, I doubt Skyteam will be any better for you than OW.