1. Cook bacon in a skillet over medium heat until crisp. Remove bacon from pan, reserving drippings, and crumble. Add the shrimp to pan, and cook 2 minutes, turning once.
2. Combine bacon, 2 cups fennel, grape tomatoes, red onion, and baby spinach in a bowl. Combine the remaining ingredients in a small bowl, stirring with a whisk. Add the shrimp and balsamic mixture to spinach mixture; toss well.