Additional note applicable only to a domestic add-on prior to connecting to an international sector
Both during booking, and afterwards on the app, the SP earn for a domestic connecting flight to an international flight will not be correct - and will show either 10 SP or 20 SP.
However, the actual earn is per the specific fare class for the city pair at the 'economy' rate. AirNZ have been alerted but seemingly have ignore this ongoing glitch.
For example, for WLG-AKL-(XXX international)
you'll earn more or less than what you saw during booking and what is shown on the app: