Great view/location, pricey at $20
The winery is located at the top of a hill that commands a view of much of Napa Valley. It is a beautiful setting.
The 'tour' is a wonderful self-guided tour, the winery beautiful. Don't expect a tour guide, though, because you don't get one.
The $20 visitor fee includes a gondola ride from the parking lot to the winery, a self-guided tour (including some videos about the history of the winery and the wine-making process), and 4-5 tastes of wine.
There are no options. It is $20 or no entrance to the winery.
The view from the patio at the top of the winery is wonderful, with a great view of nearby Castello di Amorosa.
$20 is a lot to pay to enter a winery. Is it worth it? It may be if this is your first visit to Napa Valley and you are not planning to visit many other wineries in the same day (paying $5-10 each).