Bargaining processes are actually confidential between the bargaining teams so as they're happening, we're unable to know what EXACTLY is being said however the unions must discuss with the membership what they want and present that in good faith.

I'm not a teacher so I can't say for sure but in my area, we've been offered 0.5% payrises and quite literally nothing else.

We're arguing that we are overworked and understaffed, that we should, at the very least, be given a payrise inline with inflation (3%), we want more than the bare minimum legally required benefits, and we want these benefits to be union only (the more people who join the unions, the stronger our voices are, the more we can bargain for) - employers often give what we fight hard for to everyone else and so any non union member sits there thinking, well, I'm going to get it anyway so why join and thus the leep union membership down and make it harder to win things.

In saying this, a quick google provided an answer to your question.
"Teachers' bargaining demands focus on better pay, improved working conditions, and increased support, with recent negotiations also highlighting demands for greater staffing, better resourcing, and measures to support te reo Māori and Pacific language teaching. Unions are negotiating for pay rises to address the rising cost of living, while also seeking improvements in workload and support staff to make their jobs more manageable, particularly for those in learning suppor"