Tex. Loc. Gov't Code § 211.0075

A board or commission established by an ordinance or resolution adopted by the governing body of a municipality to assist the governing body in developing an initial comprehensive zoning plan or initial zoning regulations for the municipality, or a committee of the board or commission that includes one or more members of the board or commission, is subject to Chapter 551, Government Code, regardless of whether the board, commission, or committee has rulemaking or quasi-judicial powers or functions only in an advisory capacity.