Trip Questions: Connecting from Mel to SYD (QF)-HKG-NY (CX)

Hi everyone,
Hoping you may be able to help. I have a trip coming up in July that Im excited by. I am connecting from Mel to Sydney wiht QF in J on a seperate ticket and then on to HKG and NYC with CX in J and F. I have a few questions that I though people here may have some suggestions/intel on. I am a QF platinum.

1 - Has anyone been able to have their bag tagged through with QF onto CX on a seperate booking. My thoughts are this could be hit and miss.
2 - What would people suggest in HKG for lounges. I have 4 hours to burn and it will be early circa 5am. Would you go to the Wing or pier for brekkie, is there a better option for brekkie or are they both the same (good).

Ausbt did a good transit guide that covers the different lounges in HK. You can find the article at:

Thought the CX lounge near gate 60 was excellent, but tried the AMEX opposite gate 60 last week and it is small but one of the best Ive been in.

Thanks for the updates and suggestions everyone.