AKL-JNB – the obvious choice is AKL-SYD-JNB with Qantas, BUT you could instead do AKL-DOH-JNB with Qatar! Qatar flies to quite a few African destinations, any of which could be substituted for JNB.
QR also flys to CPT & DUR in South Africa. As a former resident of JNB (for ~2 years) any thing is better than Jo'burg.
The QR AKL flight currently flys AKL-(ADL)-DOH. They used to fly AKL-DOH non stop..
To maximise ff earnings going from the extreme of 1 continent to extreme/middle of the next is better than taking the shortest flight between continents. Example for North America to Oceania (AU/NZ) on QF JFK-(AKL)-SYD is better earning than HNL-SYD but the same 1 segment. (JFK-AKL-SYD earns as JFK-SYD as is 1 flight number)
A map from the Great Circle Mapper - Great Circle Mapper