Mendip DC Liberal Democrat Lloyd Hughes said he was 'well confused' by the ruling, claiming that as he knew 70% of the businesses in his ward he would have to disqualify himself from most planning applications.
The ombudsman said he and an unnamed councillor should have declared an interest when the club's application for floodlighting was considered.
A resident opposed to the application complained to the ombudsman that the two had social links with the club.
He told LGC: 'Where you draw the line I have not had explained to me.'
The second councillor, who had once been vice-chairman of the club, was guilty of maladministration but cleared of breaching the code of conduct.
because he had not been involved with the club for two years.