Preheat oven to 350 degrees. Cut a thin slice from the top of the bread and set aside. Remove the center of the bread loaf, leaving about a 1-inch thick shell. Cut the removed bread into bite-sized pieces. Cover the shell opening with the sliced-off top and place on a baking sheet along with the bread pieces. Bake about 15 minutes, or until lightly toasted. Remove from oven and allow to cool. Place the bacon in a skillet and fry over medium heat until crisp. Transfer to a paper towel-lined plate to drain. While the bread is toasting and the bacon is frying, combine the softened cream cheese, mayonnaise, onion powder and salt. Add 1 1/4 cups of the shredded cheese to the cream cheese mixture, reserving 1/4 cup for garnish. Add the finely chopped tomato and the chicken to the cheese mixture. Crumble the bacon right into the bowl, reserving some for garnish. Gently stir mixture just enough to combine. Place the bread bowl onto a serving platter. Spoon the dip into the center of the bread bowl. Top with the remaining 1/4 cup shredded cheese, crumbled bacon and shredded lettuce. Place toasted bread pieces around the dip on the platter for dipping. Or use toasted baguette slices and save bread cubes for stuffing, bread pudding or homemade croutons.