I would also agree with the Waiheke recommendation. The ferry ride over is lovely, the island is fairly small so for the most part nothing is too far away (except perhaps Man O' War), the scenery is delightful and there are stunning restaurants too. As gambda mentioned there are lots of organised tours that would take you to a selection of Waiheke wineries. If you're really feeling energetic you could rent an e-bike but the hills on Waiheke island are not to be trifled with, even with electric assistance!

There are lots of fancy destination restaurants on Waiheke but one simpler and cheaper one that we really enjoyed, situated on a high point of the island so with sweeping views, was Batch: https://www.batchwinery.com/waiheke-...mass-bach.html (disclaimer: this was about 4 years ago so hopefully it's still good). Their wine was nice too.

Villa Maria is also a great recommendation - they are a big producer but a high quality one, and the wines on offer for tasting are their more premium and unique ones so make for an interesting snapshot of NZ wine. They have quite a nice restaurant too.