I've ended up here as looking for a solution to the same issue. Its not an issue with DBSEO at all. Its just Webmaster tools is sending out emails with advice to make your website mobile friendly.
I was going to look into reskinning the website for mobile devices.
I have made a few websites with a liquid template in dreamweaver which detects screen resolution and uses a particular css, even changed the CSS when you rotate your mobile device. This would be nice if vbulletin could do the same. It would make Webmaster tools happy.
We have users that use tapatalk on mobile devices, but I want to also have a web browser version for mobile, and control of the CMS is laid out on mobile devices.
I'm not sure where to start, sorry to hijack the thread, but I think we are both heading down the same road.
So really after some advice from the experts of vbulletin mods on how to make the website detect a mobile device and lay out the page differently, like a 250pixel wide template.