If you want the language bar to be displayed on all pages, including pages showing single news items or blog posts, you can actually put it on a template after
you upload it in Sitefinity. Go to Pages -> Templates, open the template you have created, and drop somewhere the LanguageBar control. Then select that template for all pages, on which you want to show the control.
I tested this with normal pages, blogs and news, and the control appears with no problem even on the pages with Single blog post and single news item.
the Telerik team