The technical answer to that varies on your exact status (formally established nonprofit, private school, school club, etc.), but the practical answer should be: everyone!
I can't think of any reason a local PTO or PTA should not share their bylaws, meeting minutes, or financial information. Yes, sharing them may invite questions, but if you're doing good work, then all of those questions have fair answers. The funny thing is that secrecy doesn't prevent those types of questions, either. Keeping information secret can lead to assumptions that you're doing something wrong.
We have tons of good resources on meeting minutes and finances and even on legalities of PTOs and PTAs. They all typically boil down to: Do good work and be proud and open about that good work.
