I have a season pass and it says I can bring a friend any day of this month for 9.99. But it’s for a different six flags park. Would that still work for this park?

You would have to call the park and verify it but if they do it at 1 Park then they should do it at the other but I do know that different rules for different areas

No

Actually it's for 25 here

No. I don't believe that will work. I received an email today saying members and season pass holders can bring as guest this month for $29.99.

Typically no, since the ticket price is different at every park