Combine water, 1 tablespoon juice, salt, red pepper flakes, and bay leaf in a large saucepan; bring to a boil. Add shrimp. Cover, reduce heat, and simmer 3 minutes or until the shrimp are done. Drain shrimp, and discard bay leaf. Set shrimp aside.
Combine remaining 1/4 cup juice, chili sauce, and oil in a large bowl; stir with a whisk. Gently stir in shrimp, tomatoes, mango, and bell pepper. Line 4 plates evenly with lettuce leaves. Divide salad among plates.