I have done wine tasting in that area but not on a cruise ship tour. The best vineyards are in the Valle de Guadalupe. We are very partial to Monte Xanic wines but L.A. Catto, Calafia and Pedro Domeq have some very nice wines as well.
There is a very quaint old vineyard right in Ensenada you can walk to from the cruise ship. It is Santo Tomas. The tour there is interesting and free as I recall. If it was not free, it was a very nominal charge. Wines here are so-so in my opinion but the tour was quite interesting.