At our shop, hub maintenance is a separate item from any of our tuneup packages. For one thing, there are too many types of hubs to include any type of hub maintenance/overhaul as a standard part of a tuneup. Problems that need to be addressed regarding the bike's hubs would become obvious during the course of a tuneup, but unless it's a simple preload adjustment (which we would go ahead and do at no extra charge) the customer would be called to okay the additional hub related item.