In a food processor pulse together cream cheese and Cheddar and Jack cheeses with mayonnaise and onion powder. Add pimentos and relish and pulse until blended but still chunky. Stir in bacon, transfer to a bowl, cover and chill at least 1 hour to allow flavors to develop. Serve with bread, crackers or chips, or spoon into celery ribs.
This dip was excellent...even without the bacon...everyone loved it!