I installed a wired backup camera on mine, with power supply for monitor and camera both coming into the cab. I wired both to the radio power wire, so both are turned on when the ignition is on. I do have an off-on switch on the monitor so it can be turned off (it came that way), but the camera is always on when the ignition is on. I usually leave the monitor on while driving, so I can keep an eye on anything I am towing, and I can also see if someone is tailgating too close to see in the mirrors.
To answer your question, yes they can both be wired to the same point, as long as the fuse on that circuit is big enough to handle the extra load.
Ken and Deanie (with Ralph the cat)
2002 Winnebago Minnie, 331C, Ford E450 chassis