You can look to Jetstar to see how this may pan out.
All Jetstar Aust/ NZ flying are VH tails. Pilots are EBA or NZ CEA. The Tasman and NZ flying is done by a mix of both contracts, but NZ CEA pilots are not allowed to fly (or even train) domestically in Australia. At the moment this is by agreement only.
See no reason why the QF situation would not use this as a template