My experiences with a bike have not been good while covered by the RAC and this is during the day.
Experience 1. Commuting home from work; bike broke down (can't remember the reason why). When RAC van arrived, the guy confirmed the breakdown and that he could not fix it; he arranged for a sub-contracted low loader to recover the bike and me. Wait for the low loader was a couple of hours

.
Experience 2. Commuting home from work; puncture in the rear tyre (the one day I did not carry any tools because I was bringing home a laptop in my rucksack). Phoned RAC; they arranged to send a low loader. Wait for the sub-contracted low loader was a couple of hours

. (I was about 20 minutes from home.) Complained to the RAC, who offered to not add this recovery to my list of callouts.
Experience 3. On a Sid Hill Summer ride-out; an ignition coil packed up so the twin cylinder engine was only firing on one cylinder. When RAC van arrived, the RAC guy confirmed the breakdown and that he could not do any more than I had; he arranged for a sub-contracted low loader to recover the bike and me. Overall wait for the for recovery was a couple of hours. A nice couple of teenagers did come out and gave me a cup of tea

. I even tried playing the sick card because I was on chemotherapy at the time, but no joy

.
My experience with a car has been better.
Experience 1. My Beetle split a metal brake line on a Lands End trial. Called the RAC explained the problem and asked they carried brake pipe and a flaring tool so I could fix it. No, they didn't, but accepted my diagnosis and arranged for a recovery low loader. The sub-contracted recovery company arrived in a reasonable time, offered me a courtesy car (I accepted), then delivered the Beetle to my home a couple of days later.
Experience 2. My beetle's battery split on a trial. By luck the RAC guy had just attended a break-down nearby and was soon with us. He carried spare batteries. Paid £90 for a new battery and we were on our way in a short space of time.
My conclusions are that the RAC do not have the vehicles to recover a bike; they have to sub-contract the recovery out. Try at all costs to fix the problem yourself. With regards to the flat rear tyre, If I'd known now what I know at the time, I'd have ridden the tyre home flat, then got a new tyre.
I'm now with a recovery company through our bank account. Their performance has good reviews, though, I've yet to use them.