Make the blue cheese dressing: Stir together the grated garlic and lemon juice in a medium bowl to form a garlic paste. Add the half-and-half, mayonnaise, sour cream, Worcestershire, 1/2 cup of the blue cheese and whisk until smooth. Gently stir in the remaining 1/2 cup blue cheese and season with pepper. Refrigerate until ready to use.
For the salad: Put the oil and bacon in a large skillet and heat over medium-high heat until it starts to sizzle. Reduce the heat to medium and cook until golden and crispy, stirring often, 10 to 12 minutes. Transfer the bacon to a paper towel-lined plate with a slotted spoon. Return the skillet with the bacon fat to the stove and decrease the heat to low. Add the smashed garlic clove and more oil if necessary and cook for 1 minute to infuse the oil. Add the tomatoes, sprinkle with salt and pepper and cook, shaking the pan often, until slightly softened and a few of the skins are split, about 2 minutes. Remove from the heat and add the bacon back in to keep it warm.
Put the iceberg wedges on a large serving platter and top with the scallions and tomatoes. Spoon the dressing on top, letting it run down the sides. Finish with the bacon.