Place red wine in a small saucepan. Simmer until red wine has reduced to ½ cup. Let cool completely.
In a small saucepan, combine water and 1 cup of the sugar. Set over medium-high heat and cook until the mixture reaches 240° per a candy thermometer.
While your sugar mixture is cooking, place egg whites and cream of tartar in the bowl of a stand mixer. Using a whisk attachment, beat mixture on medium speed until soft peaks form. Slowly add ⅓ cup of remaining sugar.
Once the sugar mixture has reached 240°, add it to the egg white mixture in a slow, steady stream while the mixer is running, making sure the sugar mixture avoids touching the whisk attachment as much as possible while pouring.
Beat on medium-high speed until the bowl of the stand mixer is no longer warm to the touch.
Switch to a paddle attachment, and add butter. Your mixture may begin to look soupy. Do not lose heart! It will come together after a couple minutes of mixing.
Stir in 6 Tablespoons of the red wine reduction.
Frost cupcakes.