Cook pasta according to package directions. Meanwhile, in a small bowl, combine the mayonnaise, lemon juice, sugar and garlic powder; set aside. Drain pasta and rinse in cold water; toss with onions and half of the bacon.
In a large salad bowl, layer half the romaine, pasta mixture, peas, cauliflower, broccoli, red pepper, mayonnaise mixture and cheese. Repeat layers. Sprinkle with remaining bacon. Cover and refrigerate until serving.