Bylaws and/or rules ensure that governance of your committee is performed with transparency and that internal disputes and conflict can be avoided. They provide a basic road map by which your committee is run and serve as a legal set of operating rules. As a political body, your county Bureau of Commissions, Elections, and Legislation or Campus Governing Office may require bylaws/rules to ensure your authority in election matters.
In seeking affiliation with the Green Party of Pennsylvania you commit to the values of the Green Party. The State Committee may cancel its recognition of any Committee if such Committee were to become unviable or engage in activities that are in blatant opposition to Green values, including but not limited to failure to adopt democratic internal procedures.
Bylaws/rules can be as simple or complex as a Committee sees fit for it's needs. An example of bylaws which may be minimally acceptable can be accessed here.