Found this great glass bottle option online .. WeeGo glass bottle by Babylife.
Babylife is reintroducing glass baby bottles, because of the recent concern over leaching chemicals in plastic baby bottles - but with a new design and safety twist: the bottle is covered with a modern sleeve that will help protect the bottle from breakage and also prevent bumping into other articles in your diaper bag.
WeeGO is baby bottle that is bisphenol A, phthalate, PVC and polycarbonate-free.
Haven't seen this in NZ, but please leave a comment if you know if any stockists.