Normally you would want to keep them apart but CB's are prone to all kinds of interference. The more isolated you can keep things away from it the better.
I'd leave the cables a bit long to start with and see if you have any interference before you make things permanent. Then you can trim them to what you need for the final location. It's easier to move something around if the cables are not secured or cut and now too short to try another location.
l We're here for a good time. Not a long time. So have a good time the sun can't shine every day.