I have iOS 7.1.1, and I'm running VLC 2.3.0.
When I am in the All Files Media Library, I have some files that have not-very-useful names. When I click 'Edit' in the upper-right, select a file by checking it and then selecting 'Rename' at the bottom center, I do get a dialog box for renaming the file, but after I type in the new name and select 'Rename' again in the box, it just shows me the library again without having applied the name change.
Please let me know if this is a known bug, or if there is some other way to apply it.