Unfortunately this scenario is not yet supported. We will be working on this functionality after our official Q1 2011 release which is scheduled for the second half of March. I've added an item in our public issue tracking system
under the name "PanelBar: Second level items cannot be styled to look like first level items"
and it will be available for tracking and voting tomorrow the latest. I've also updated your Telerik points accordingly. Let me know if you have further questions or comments regarding this issue.
the Telerik team
Registration for Q1 2011 What’s New Webinar Week is now open. Mark your calendar for the week starting March 21st and book your seat
for a walk through all the exciting stuff we ship with the new release!