Have booked flights LAX/JFK/LAX on AA through zuji.com.au to supplement my MEL/LAX/MEL flights on QF93 and QF94 (work trip).

Just wondering about a few things:

I'd like to connect the two bookings. The AA flight JFK/LAX is connecting to LAX/MEL on QF94, and I guess I'd like QF to know if there are any delays on the JFK/LAX leg. Should I contact QF or AA (or doesn't it matter) to connect the two bookings?

As a QC/QP member, I assume that I will be able to use the Admirals Lounge at JFK prior to JFK/LAX flight. How about at LAX? As I'm arriving in Terminal 4, will I be able to use the Admirals Club there or will I need to use the club in TBIT?

I assume my luggage will be through-checked to MEL from JFK?

Any other words of advice?

Cheers,
John