First of all, this is not for me. I am a fat 65 year old man who likes to eat bbq and drink expensive scotch. But, I have a coworker is is a very fit 40 year old female. She wants to do a vineyards tour by bicycle with her boyfriend for her birthday.

Anywhere in the contiguous 48 states would be amenable.

Anyone have any ideas?

We did one in Napa.

Turns out there are a lot of bicycle rental places in the area. Part of the rental is that they provide and deliver lunch at the winery and time of your choosing. They have maps and itineraries. It was seamless and great. Now... a day full of red wine and scenery makes the ride home tedious

Napa is the first answer.

Willamette is the only other. McMinnville, Dundee, Carlton, etc have great wine, even better scenic country roads of farms, covered bridges and volcanoes. Silver Falls and the Trail of Ten Waterfalls is must nearby. The OR coast and it's fab rides an hour away. If you value the quality of cycling at all, OR is top notch, imo. But I'm extremely biased.

Edit: I found a good sample iternary with routes - https://www.lifecycleadventures.com/wp-content/uploads/2022/11/no-price-SG-OR-V0.1.pdf

We did this one out of Yountville

https://napavalleybiketours.com/


By the end of it, my sac hurt and i was wine cranky ... but my wife loved it.

Finger Lakes region of NY might be a decent option as well

If they go to Napa, I recommend eating at Hog Island Oyster Company. It's a casual setting in a nice farmers market and they control their own oyster production.

I've never done it and don't really know dick about wine but there's quite a few folks on bikes in the Santa Ynez valley here on the weekends going between all the different wineries between Los Olivos, Solvang, Buellton, Ballard canyon, etc.

We did a few Russian River wineries on E-bikes from Pedego in Santa Rosa.

https://pedegoelectricbikes.com/dealers/santa-rosa/