Final Plat Filing - Texas

When does a Final Plat become legally binding for a boundary survey in Texas?

If a property goes through a muicipality's platting process, and (according to minutes) is approved by City Council with conditions that are to be met, yet is never filed of record at the county clerk's office by the City, is it a legally binding plat?  To add to the issue, no one knows for certain if the conditions were ever met.