Dissolve bouillon cubes in hot water; set aside. Cook bacon in a pan until crisp; remove bacon, reserving 2 tablespoons drippings in pan. Drain bacon on paper towel.
Add onion and celery to drippings, and saute until transparent, stirring frequently; drain. Add bouillon, tomato, and next 6 ingredients; bring to a boil. Reduce heat, and simmer, uncovered, 20 to 25 minutes or until lettuce wilts. Top with bacon and croutons. Serve immediately.