Nntexas, I've tried about 40 times to send you a useful link for the bus schedule for Waiheke. Google "at metro bus schedule waiheke" then click on the PDF for Waiheke bus &ferry.

Diamintina, You are so kind. I think I saw the route and timetables on the Fuller Ferry site. We decided to opt for lunch that day and will probably do the Hop on/Hop Off combo ticket with the ferry that day.

Y'all need to come to Texas for some of our Tex Mex food. Our local grocery carries, believe it or not, dynamite guacamole. Yum!

The Shed at Te Motu is my favourite restaurant in the North Island! You won't be disappointed eating there. Lunch is probably the better option but we have been there for the 'fish Friday'. We were staying there and had our car that visit so transport was no issue however it would pay to check the bus.
Diamantina has given great info about the bus so I won't cover that.
Otherwise in Auckland city I like Mikano. Great for fish but then hubby always has a steak and that was good too.

Sorry Nntexas, I did my time in Texas (five years) and I hope to never go back! No complaints about the food, but the heat, humidity, bugs, traffic, lack of mountains, lack of snow....not for me.

Melnq8--no worries. I love the heat but we are not having a typical TX winter this year. Thank goodness that we all have options :)
We did decide to opt for lunch at The Shed. I expect we'll do the Hop On/Hop Off bus too.

Tex Mex & guacamole sound good to me. I haven't been to Texas in more than 30 years. But I wouldn't mind renewing my acquaintance, and visiting Marfa, the Dallas Museum of Art, and doing some birdwatching in its national parks and wildlife refuges. Though I'd probably wilt in the heat.

I think you'll be happy with your decision to book lunch at The Shed. It's it's a fine day, you'll enjoy the day time views. You'll also have a chance to do some wine tasting at other wineries. Besides those that are walking distance from Te Motu, you might want to stop at Cable Bay and Mudbrick. Mudbrick is about a 7 minute uphill walk from Cable Bay. If you visit Cable Bay toward the end of the day (the cellar door closes at 5, but I'm not sure when the Verandah closes), then you can just walk from Nick Johnstone drive down to the ferry terminal when done. It's a pretty 15 minute walk on a well-maintained track through a forest and bird reserve (Atawhai Whenua Reserve). Cable Bay Winery's website shows how to get from the winery to wharf via this walking track.
Mudbrick Vineyard & Restaurant | Wine | Food | Ambience
https://cablebay.nz/dining/the-verandah/
https://cablebay.nz/our-story/gettin...erry-terminal/

Or you might want to stick around the island for, or catch the ferry back at, sunset. I see The Batch stays open later, is on the Hop On Hop Off route and boast of their sunset views. I seem to recall Auckland-expert Tasmangirl suggesting The Batch. I never got around to visiting it.
https://www.batchwinery.com/
These are sunrise-sunset times for New Zealand. I've caught the Waiheke ferry back to Auckland at sunset and it was nice (but it was one of those perfect days).
http://rasnz.org.nz/in-the-sky/sun-rise-and-set

Peacock Sky Winery also has a great location and is on the Hop On Hop Off bus route.
I love Onetangi Beach and its Hauraki Gulf views.

Diamantina,
Those are great suggestions! Thanks so much for the additional info.
All sounds fantastic!