PLACE cheese, mustard, margarine and pepper in food processor or blender container; cover. Process until well blended.
BRING wine just to boil. With food processor running, gradually add wine to cheese mixture, processing until well blended. Place in medium bowl; stir in bacon and onion. Transfer to serving bowl, if desired; cover.
REFRIGERATE several hours to allow flavors to blend. Let stand at room temperature 1 hour before serving. Serve with crackers.