https://bugs.winehq.org/show_bug.cgi?id=42606
--- Comment #4 from Rafał Mużyło galtgendo@o2.pl --- Not really.
It's kind-of-yet-not a theming issue.
The way wine caches theme fonts is with their charset.
The problem here is that if your standard charset and the one of the locale you're overriding it with don't match, 'funny' things may happen.
That's bit hard to simulate on Windows, as there locale switch forces necessary font changes.