Make the wine syrup: Add all ingredients for the syrup to a small saucepan over medium heat. Heat, stirring often, until sugar is dissolved and syrup starts to bubble a little (about 5 minutes). Allow to cool to room temperature. Strain and refrigerate. (I'm guessing this stuff will keep a few weeks in the fridge.)
Add all ingredients except the Prosecco and the garnish to a cocktail shaker filled with ice. Shake until very cold. Fine strain into a chilled flute or coupe. Top with Prosecco, garnish with the twist, and serve.