https://bugs.winehq.org/show_bug.cgi?id=41996
--- Comment #9 from Andrey Gusev andrey.goosev@gmail.com --- (In reply to Connor McAdams from comment #8)
D3DFMT_V8U8 is now supported in d3dx9 since 6d9ae6b56f859a331343a015527020a2ae91b7f8, probably worth re-testing this to see if that was the issue.
Bug 46779 should be implemented first.