In a large saucepan, combine first nine ingredients; bring to a boil.
Meanwhile, place flour in oven bag; shake to coat. Place oven bag in a 13-in. x 9-in. baking pan; add the bacon. Sprinkle rice and mushrooms over bacon. Add pheasant. Pour soup mixture into bag.
Cut six 1/2-in. slits in top of bag; close bag with tie provided. Bake at 350° for 1 to 1-1/2 hours or until a meat thermometer reads 180°. Let stand for 10 minutes before carving. Yield: 6-8 servings.