The little white bugs are Grape vine leaf hoppers. A few are ok, but they can kill a lot of leafs if not taken care of. The grapes will not ripen if to meany leafs die.
Good afternoon KWPR, I live also in Paso and a member of Wines and Stine's. We may have met. The photo is a little hard to see the vine up close. Have you used any herbicide? If so that could be your problem as the leaves look damaged.
Why do I make Wine? I planted over 500 vines so I have to do something with the fruit. Just kidding. I enjoy Wine and most of the work that goes into being a Wine grower. I make about two barrels a year.