It's not time in NZ that makes any difference - it's being able to show solid evidence of at least 12 months' living together. You evidently made a good case and got your partner-sponsored work visa, proving however long you did. You need to keep on collecting evidence that you're still living at the same address, moving around together if you go on holiday, etc., as that is what the INZ CO will need to see to be able to tick the boxes to give you the next visa. What you need is just more of the same.
(Have you seen the old threads? You may get some extra inspiration there.
https://www.google.co.uk/#q=site:enz...tnership+proof)
You may well find that it takes INZ a long time to process your application for Residence, judging by the fact that this often happens for people who are already in NZ on a temporary work visa of whatever kind. It's as if INZ think, 'This person is already legally here and working, so they don't need the rush as much as people who need their first visa to start earning their living.' So it's possible that things could drag on till you're getting towards the end of your work visa. If you get within eight weeks of the expiry date, and write in saying it will shortly expire and will your Residence be through in time, it has happened to many other people that their Residence magically appeared within the next week or so.