Cook bacon in a large Dutch oven until crisp; remove bacon and drain on paper towels, reserving 2 tablespoons drippings in skillet. Crumble bacon and set aside.
Sauté onion in hot bacon drippings over medium heat 5 minutes or until tender. Add potatoes and sauté 5 minutes. Add clam juice, Worcestershire sauce, and thyme. Bring to a boil; reduce heat, and simmer 15 minutes or until potatoes are tender. Add fish, and bring to a boil; reduce heat, and simmer 5 minutes or until fish flakes with a fork. Add milk and remaining ingredients. Cook over medium heat until mixture is thoroughly heated. (Do not boil.) Serve topped with crumbled bacon and thyme leaves.