Bring a large pot of lightly salted water to a boil. Cook rotini at a boil until tender, yet firm to the bite, about 8 minutes an drain.
Place bacon in a skillet over medium-high heat and cook until evenly browned. Drain and chop.
In a large bowl, mix mayo, ranch dressing mix, garlic powder and garlic pepper. Stir in milk until smooth. Place rotini, bacon, tomato, black olives and cheese in a bowl and toss to coat with dressing. Cover and chill at least 1 hour in refrigerator. Toss with additional milk if the salad seems a little dry.