No! The fan on the urine diverting toilet should be the only fan in the room. It runs continuously and will circulate the air in the room and vent the moist air from any shower etc. An additional wall mounted fan may cause a small vacuum effect in the room, drawing smell from the toilet in the wrong direction.
For UK customers, the Building Regulations specify that the room the toilet is in (the WC) should have either an opening window and/or a fan – the capacity and type of fan is not specified, so the fan in the Villa will satisfy the Building Regs requirement if no opening window is present.