The wine's tartness, tannins, and booze all dull down, instead bringing out a gentle fruitiness. Ginger ale adds a delicious dose of sugar, while still offering a gentle kick.
Paired together, the drink is extraordinarily sippable, especially since it's both chilled and bubbly. You can throw in berries, citrus, or even rosemary to keep flavors dynamic.
Cheap red or white wine both work in this formula, so suit your tastes. For a red wine, consider a bold, fruity Nebbiolo; for a white wine, try the crisp and fruity pinot grigio.