As quite a few people mentioned before, tracking numbers don't show up on the NZ Post site straight away.
PetAT: ... but I wont be using them so I listed them back up on trademe for sale...
I wouldn't list until I had then on my hands - what happens if you sell those but they don't show up? You'd be the one getting a bad feedback from the buyer then.
I say wait before listing. If listed, remove until you have all of them.