In fact, oneworld status is available and visible to all oneworld carriers, and is now printed on all boarding passes. The upgrade privileges do not carry accross carriers (except CP and AA) but priority seating should.
Again, it sounds like at least CX and BA are not quite living up to the promises made by oneworld. (Can't speak to QF as I haven't flown them, and AA and CP are no problem for me, as a CP Exec Plat.) Smells like trouble to me.
Regards,
Ken Hamer