Legal Question in Criminal Law in Texas

I don't know of any legal limit, but realistically, that's normally a self-limiting situation--if he can be transferred to the county jail, he will be, because otherwise the municipality is having to pay to keep him housed at their jail unnecessarily, and they're not going to want to do that. The only situation I can think of where they'd keep him at the municipal jail for any length of time would be if he was serving out tickets, in whch case they'd keep him there until that was taken care of, and then transfer him to the county jail to deal with whatever he's got there. He'll get pre-trial jail credit regardless of which jail he's in, if that's your concern.