Hi, Being a ex RAC employee, I was a Service patrol for a good number of years, I can confirm that with normal RAC cover a breakdown on your caravan is not covered, and it cannot be added as a option. If your car breaks down whilst towing your caravan then both will be recovered if the fault cannot be fixed at the roadside or at a garage within a reasonable time at a reasonable cost.
If you take out the Arrival cover through the C&CC then any problems with your caravan e.g. Puncture , problems with external lights or accident damage will be attended, not always by a patrol, in a number of cases a garage agent will be sent especially if the caravan will need recovery, in a good number of cases this will be the same garages that Green flag use for their Caravan Club Mayday service, this can be something of a lottery as to the kind of service you receive some are very good and some are equally very bad dependant on where you are unfortunate enough to breakdown.
Hope this helps, By the way I have Mayday cover through CC and having 3 vehicles with comprehensive and extra cover at a cost of just over