Combine first 3 ingredients; set aside.
Cook bacon in a large nonstick skillet over medium heat until crisp. Add onion, bell pepper, and garlic to drippings in pan; cook 5 minutes or until tender, stirring occasionally. Stir in shrimp mixture, broth, and 1/4 cup green onions; cook 5 minutes or until shrimp are done, stirring frequently.
Bring water to a boil in a medium saucepan; gradually add grits, stirring constantly. Reduce heat to low; simmer, covered, for 5 minutes or until thick, stirring occasionally. Stir in butter and salt. Serve shrimp mixture over grits; sprinkle with cheese and remaining green onions.