A wine cocktail is a mixed drink, similar to a true cocktail. It is made predominantly with wine (including Champagne and Prosecco), into which distilled alcohol or other drink mixer is combined. A spritz is a drink that has Prosecco added to it.
The distinction between a wine cocktail and a cocktail with wine is the relative amounts of the various alcohols. In a wine cocktail, the wine product is the primary alcohol by volume compared to the distilled alcohol or mixer.