Can I connect multiple bare wires to one DC Power connector?
I am struggling my self at same situation as yours. 
What I have identified is that you have to make sure you power supply has current enough to cover more current than your whole system need. I am planning to build up a 8 cam cctv and I definitely will use a terminal block to connect all power wires into it and in the other side just two wires from the power supply. 
So answering your question, I'd use one connector per camera and I will definitely connect all cam power cables in same power supply output (thorough terminal block).