Steam potatoes until tip of knife easily pierces center of slices, about 10 minutes. Transfer to large bowl. Cover with foil.
Sauté bacon in large skillet over medium heat until brown, about 3 minutes. Using slotted spoon, transfer bacon to paper towels. Discard all but 2 1/2 tablespoons drippings. Heat drippings in skillet over medium heat. Add onion; sauté 2 minutes. Whisk in next 6 ingredients. Simmer until mixture is reduced to 2/3 cup, about 4 minutes. Remove from heat.
Add potatoes to skillet and toss to coat with dressing. Let stand 3 minutes. Sprinkle with chopped bacon and fresh dill; toss. Season to taste with salt and pepper. Transfer potato salad to serving platter. Serve warm.