Heat a large Dutch oven over medium heat. Add bacon to pan; cook 5 minutes or until browned, stirring occasionally. Add onion, celery, and chopped thyme to pan; cook 8 minutes or until softened, stirring frequently. Add potato and bottled juice; bring to a boil. Reduce heat to medium-low; cook, covered, 9 minutes or until potatoes are tender.
Stir in corn and mussels; bring to a boil. Cover and cook 5 minutes or until mussels open; discard any unopened shells. Combine half-and-half, milk, and flour in a small bowl; stir with a whisk. Stir half-and-half mixture and clams into pan; cook 2 minutes or until slightly thickened. Stir in 2 tablespoons reserved clam liquid and salt. Garnish with thyme sprigs, if desired.
Tomato and fennel salad: Combine 4 cups torn romaine lettuce, 1 cup halved cherry tomatoes, and 1 cup sliced fennel bulb in a large bowl. Combine 1 1/2 tablespoons balsamic vinegar, 2 teaspoons honey, 1 teaspoon Dijon mustard, 1/4 teaspoon salt, and 1/8 teaspoon freshly ground black pepper in a small bowl. Gradually add 1 tablespoon extra-virgin olive oil, stirring constantly with a whisk. Pour vinaigrette over lettuce mixture; toss well.