It means that the water is run, and probably owned, by a small group of anglers. Membership is limited and sometimes by invitiation only. Vacancies only arise when a syndicate member leaves or they expand the syndicate. £130 sounds like a yearly fee - there are some which charge significantly more per annum!!
There are some traditional angling clubs which have waiting lists because they have a cap on numbers -and their range of waters is so large and varied that more people wish to join than the have vacancies for in any one year. An example of thisis the prince Albert Angling Society - which is based inthe North West but has many waters further afield.