Wine's printing support isn't perfect. You should probably file a bug. The ususal workaround is to store your docs in a pdf, jpg, etc if they aren't already in that format, and open it with a native linux application and print from there, apps like adobe reader, kpdf, gwenview should have the options to print landscape. This isn't quite comfortable, but should work. No need to feel lost. Wine is still in some beta state if you for instance define production quality as "all userland WinXP apps should run fine" (userland means apart from drivers and system-/hardware related stuff like defrag tools).
