Originally Posted by
percysmith
I thought the answer was no, based on the Vietnam-US fares when the HK-Vietnam leg was codeshares on VN (Business/First access mirrors OWE/OWS access).
But the lounge access on CX- or KA-marketed flight is an MPO thing. CX is more generous to its own members and customers in lounge access. For example, when connecting between 2 CX / KA flights on one ticket, as long as one sector is F or J, you get lounge access all the way. This is also more generous than the oneworld rule.