Key point is that while alcohol can easily be turned into triglycerides, it’s not so easy to do gluconeogenesis with it. Since you can’t turn it all into glucose, you can’t refill your glycogen stores with it. Every gram of glycogen comes with 3 grams of water. You’ll end up losing a lot of water weight in a few days even if you’re in a calorie excess because of the relatively low carbohydrate profile of this diet. If you drink enough wine, the sugar from the wine will allow you to rebuild your glycogen stores so that’s why this diet limits it to a bottle.