There have been a few changes at LBA recently in this regard.
Prior to about the middle of March ground vehicles were controlled on a distinct UHF frequency which was often manned by the Tower ATCA under the ATCO's licence. There was no cross-coupling and the Tower controller frequently had to keep an ear on the UHF and VHF frequencies simultaneously. Then, to coincide with a new VCCS, the two frequencies were cross-coupled, meaning the ATCA now does no talking and the ATCO does it all. Slightly more work in the hotseat but effectively only having to monitor one frequency. Swings and roundabouts really. I believe it was introduced as something to do with European safeguards against runway incursion. Correct me if I'm wrong.
I would have thought if operators of ground vehicles were to be using Aeronautical VHF frequencies as opposed to an airfield's indigenous UHF frequencies they would have to be licensed by the CAA.
Interesting thread this one. Over to you...
