For dressing, process oil, vinegar, sour cream, whipping cream, mustard, green onions, garlic powder, lemon peel, salt, and pepper in a food processor until smooth. Cover and refrigerate 8 hours or overnight to allow flavors to blend.
For salad, plunge lobster tails into enough boiling, salted water to cover. Bring to rolling boil again. Boil 10 to 15 minutes or until lobster turns pink; drain. Plunge lobster into cold water and drain again. Cover and refrigerate until well chilled. Remove lobster meat from shells and cut meat into 1/2-inch slices. Cover and refrigerate until ready to serve.
In large bowl, toss bacon, lettuce, red onion, and tomato. Divide salad evenly into 8 bowls. Arrange 3 to 4 pieces of lobster on top of each salad. Spoon about 2 tablespoons dressing over each salad. Garnish with green onion.