You can set a specific template to use for a Page Tab. Our template is optimized for mobile when you navigate to it directly, but not so much when viewed within a Page Tab.
With that said, I don't see the Page Tab in mobile view either. I'm logged in as an admin though, which makes it difficult to see a 'users' perspective. We'll have to investigate more to see how and if a Page Tab can show in mobile. It definitely used to be able to.. and a link to the Page Tab works.. but without an actual 'tab' in mobile, that's not very helpful.