Preheat oven to 400°.
Cut bacon into 2" pieces and cook until pieces just begin to brown. Place onion wedges in a 9 x 13 baking pan. Tuck the cooked bacon pieces into the onion wedges.
In a small bowl, whisk together the vinegar, water, maple syrup, oil and spices. Pour mixture over the onions. Season with salt and pepper to taste.
Cook the onions, basting frequently and adding water a little at a time as marinade evaporates. Cook until tender and covered with the syrupy glaze – about 45 minutes.
Serve onion wedges hot, with bacon and pan drippings drizzled over each.