Pros:  Winerys are great for first dates for three reasons. Alcohol, Alcohol, Alcohol.  Haha, just playing.  However, alcohol is a common feature at winerys, it's also usually accompanied with GREAT scenery, and great food.  You hardly see these now a days, so you will definitely get points for it being a rare date.

Cons:  Depending on the type of person you are, alcohol could be a problem.

Notes:  Winerys aren't for getting drunk.  They are for relaxation and tasting.  Make sure you keep that mind and try not to drink too much.