Preheat the oven to 350 F. Place the potatoes in the pot, cover with water, and bring to a boil. Cook for about 20 minutes, or until the potatoes are easily pierced with the knife. Remove from the heat, drain, and let sit until they are cool enough to handle. Cut the potatoes into small dice and set aside.
In the sauté pan, cook the bacon over high heat until browned. Drain, leaving 1 tablespoon of fat in the skillet and add the onion. Cook over moderately high heat for about 5 minutes until golden brown then add the bacon and wine and cook for another 5 minutes, stirring occasionally. Add the potatoes and season with salt and pepper.
Remove the potato mixture from the heat and place half of it in the ovenproof dish. Spread half the cheese slices atop the potato mixture. Cover this with the other half of the potato mixture. Top with the remainder of the cheese. Bake in the hot oven for 20 minutes, or until golden brown and bubbling. Serve hot.