http://bugs.winehq.org/show_bug.cgi?id=58452
--- Comment #2 from Rafał Mużyło galtgendo@o2.pl --- Unless I'm seriously misunderstanding you, you seem to be doing things wrong.
For at least a decade pretty much all Linux distros have been advising their users to use UTF-8 locales.
So, clarify what do you mean by 'resulting in garbage latin characters for cyrillic text'.
As long as your system is using an utf-8 locale, the filenames should be fine, regardless if it's ru_RU.utf8 or uk_UA.utf8. The text in the text files depends on the codepage the editor is using - if it's UTF-8 or UTF-16, there should be no difference based on locale; if it's an 8-bit codepage, those aren't compatible by design.