Any CX flight in J or F has Wing/Pier lounge access. KA flights do not (most of the cheap flights ex-HKG are KA). XMN flights are operated by KA but have a CX codeshare; I think if you book the CX codeshare you get CX lounge access, but better check with CX about that -- the KA code definitely does not (KA has a separate lounge at HKG, which is nothing like the Wing/Pier).