A bit of back to the future here. I took a QF codeshare on NZ metal LAX-AKL (QF101 I think) back in 1991 (I think). And I am pretty sure they have codeshared trans-Tasman in the past, back when QF had some ownership in NZ (maybe around 1990). They certainly had the same fare and ticket validity for QF and NZ trans-Tasman