Originally Posted by
Top of climb
Correct insofar that the entire journey is on one ticket. But if (a) NAN-AKL-SYD is on a separate ticket; and (b) both NAN-AKL and AKL-SYD are both on Air NZ then 302 simply doesn't apply because there is no interline. NZ applies the higher allowance at NAN check-in as per its own rules.
In post one the OP did not include the USA origin.
They made it clearer in post #4 which changed the answer(s) somewhat. They still have not specifically answered the question about travel being on the one PNR.
I have taken the OP as meaning the whole journey is booked on the one ticket.
I'm not sure the OP is aware of how important their answer to the "one ticket" question is. Until they answer that, much of what we can provide is in specific case "what if" scenarios.