It all depends on where your going to be touring and your likes and dislikes, joining one of the clubs can give you cheaper caravan insurance, and breakdown recovery.
I have probably only used either of the clubs main sites maybe less than 10 times in 15 years, as the location of, most, of the sites do no suit us, but the selection of the smaller Cl / Cs sites (only up to 5 caravans at a time) do suit us better.
But we have also found that private sites, can be much better value for money and at times are better situated for our liking.
Have a look on
https://www.ukcampsite.co.uk/index.asp?mob=n for sites, around where you want to go, and see if it is worth joining a club.
We have been members of both clubs for over 15 years.