VSTs work perfectly fine in Bitwig. Whether a plugin supports linux is a different question though. I've tried to run windows VSTs via yabridge under linux but that was barely usable.
Yes, I remember trying to set up Omnisphere and it just wouldn't work for me. So my issues were related to windows VST's. I used Wine and yabridge, which did install them but they weren't usable.
Was that some time ago? I find Yabridge to work reliably on numerous plugins.