I am a tour guide and I brought my client to the gardens

I am a tour guide and I brought my client to the gardens. My client went into the gardens and said that I could wait in the vehicle for her. I do this most of the time waiting for my client in the vehicle while they are inside. The security approached me and said that I am not allowed to sit in the vehicle but the bus drivers can. They want us to wait on a bench for 2-3 hours for our clients or go right outside the gardens and wait. I find that it is very unfair that the bus drivers can sit in there busses but us tour operators must sit like kids on a bench or leave the premises. This is not on because it is bad for our visitors and to make them feel safe. This is very disrespectful and unfair. What goes for one should go for everybody.