In a heavy, 4-quart saucepan over medium-low heat, melt the butter. Add the tomatoes and saute, stirring frequently, until the tomatoes just begin to soften, about 2 minutes. Add the package of Hidden Valley® Original Ranch® Salad Dressing & Seasoning Mix and stir gently to dissolve the seasoning mix.
While the tomatoes are cooking, combine the flour and cheese in a bowl and toss to coat the cheese.
Add the wine to the tomato mixture, stir once, and then add the cheese, a handful at a time. Heat and stir until the cheese is completely melted. Transfer to a fondue pot set over an alcohol or sterno flame to keep it warm. Serve immediately.
Serve with crusty-hard peasant bread cut into 1-inch cubes, pita chips, bagel chips, or tortilla chips.