I suggest between a teaspoon to a tablespoon per gallon. How many vines do you have?
It is easier to calculate when you have grown vines and know how much spray you need for each spray. If you have a quarter acre of vines, you use a pound max in however much water you need to spray the vines. For baby vines I go light so you could manage wit a teaspoon per gallon.
For example, I have 1.12 acres of three and four year old vines. I have a 55 gallon sprayer on my tractor. It takes two and 1/2 tanks to spray 1.12 acres. To keep it fairly simple, I divided four pounds by 137.5 gallons or by 2.5 tanks and decided that I needed 25.6 ounces or 1.6 pounds per tank.