if it’s the same airline, they should guarantee your connection. minimum is 50 mins.
i flew airnz to chc, but need to clear immigration at auckland. was very delayed there and missed our connection but they just put us on the next flight to chc. there were a few other pax who were also affected and it was a bit unpleasant because instructions given were not clear.
Air NZ is different from Qantas. AKL to CHC is a domestic flight and there are many flights between the two cities. It is easy for Air NZ to do that. Whereas AUS to NZ is an international flight. So, if you miss the flight, it will be going to the next available flight which might be hours away.