If you had flown OneWorld then you could've gone to the CX lounge.
As you're flying EK, a OneWorld lounge is not an option.
The special champagne is on request for P1 and CL in premium lounges e.g. HKG. It's a pretty good lounge as far as QF lounges go, but it's not in the same class as the QF FLounges in MEL and SYD.
If you have enough time perhaps you could try both lounges?