Heat olive oil in a large skillet over medium-high heat and brown ribs. Remove to 13 x 9-inch roasting pan; set aside.
Add onion to same skillet and cook onion over medium-high heat about 4 minutes or until tender. Add garlic and cook 30 seconds. Stir in vinegar and 2 tablespoons wine scraping up brown bits from bottom of skillet. Stir in water and next 3 ingredients until smooth. Pour sauce over ribs. Cover with aluminum foil. Bake for 2 hours or until ribs are tender. Degrease pan drippings. With wire whisk, blend remaining wine and flour until smooth. Add to pan and boil for 2 minutes or until thickened. Serve gravy with ribs.