I use to carry an air compressor when we drug along our bicycles. Other than blowing up bicycle tires for other camper's kids, I've never had to use it for anything of my own. After carrying it for years and years, I started leaving it at home. Never missed it.
To bring along an air compressor or not? It's really what you need it for. If you still need to air up those motorcycle tires, then by all means, bring it along. If you no longer travel with the motorcycles, leave it at home.
More important than the weight, which is really insignificant for your rig combination by the way, is the space it takes to haul it with you. Do you need that space for something else? If so, leave it home. If you have real estate space available for it, then bring it along. Space is the determining factor, not the weight.
It's your call. How important is it to you to bring it along? Only you can answer that question.