To prepare the pinot noir syrup: stir the pinot noir and sugar in a small saucepan set over medium heat. Bring to a boil and continue to cook until the contents of the pan have been reduced to 4 ounces, about 15 minutes. Allow to cool and chill completely in a heat-proof container in the fridge. The syrup will make about 4 Pinot Ritas.
To prepare the pinot Rita: salt the rim of your glass, if desired. Combine the tequila, lime juice, pinot noir syrup, and Cointreau in a cocktail shaker. Fill the shaker with ice and shake vigorously for about 30 seconds. Pour the entire contents of the shaker into the prepared glass. Serve with a lime wedge, if desired.