I think the standard mix is a tablespoon per gallon (I mix 1 teaspoon to 1 quart which works perfectly fine as well) so that would be 2 tablespoons to 2 gallons
I don't use neem oil anymore but I would mix that according to label directions, I would also not mix them together I would treat with one first, and then the other next treatment for best results ?
-good luck!