We did the daytime event a few years ago.
You take a class on harvesting grapes and then are assigned a row to work. It's hot outside but it was fun and not too taxing. Basically just harvest along a stretch of vineyard and then return your grapes to the big containers.
Then you get to stomp the grapes and make a T-shirt. Everyone pretends they are Lucy in Italy and they take pics, etc. It's goofy but everyone seems to have a good time.
At some point in the day, you take a tour of the winery. When we were there, they would put a photo of you in the vineyard on a bottle you could purchase.
The nighttime events feature dinner, I believe.
We enjoyed it; it was a little more active and involved than your typical winery visit.