If you are referring to Multisim, then I have not been able to do anything with the bus labels except move them around or lock them in position.. All the rotate and delete options are greyed out and unselectable, I even tried going into sheet properties and turning everything off there to see if I could get rid of the label so you could try and place text on it to do what you want None of this worked, so this may have to be a feature request.
