It looks like the site for the Wellington supercharger has been decided and shouldn't be far off! http://investoreproperty.co.nz/documents/Investore_Property_Limited_Interim_Report_HY20_131119.pdf The TL;DR summary is that they're being installed at Countdown Johnsonville
Why Jonsonville and not Wellington CBD like Auckland's are. Seems a strange place as somewhere along the street where BMW dealership are would be better. If you live within 300k return you wouldn't use Tesla's supercharger and pay almost double you would charge at home.
Johnsonville is ideal for access from SH1. For someone travelling to/from the ferries, or who's destination is elsewhere in Wellington, the CBD can be quite a detour - especially if there is traffic!
Sorry I missed this one earlier! I'll add it to supercharge.info. Notice some odd statements in the document - it suggests 3 stations (literally, an odd number!) and also says "for the new Tesla Model 3" (I assume they just mention the Model 3 because it was new at the time).
Twitter clearly has a script to flip photos from the southern hemisphere the correct way up, why doesn't TMC?