I have created a theme where my WorkShelf and Startbar use essentially the same graphic, and forced WorkShelf to overlap the startbar. This gives the appearance that the two products are "merged" into one coordinated graphic. This works great in collapsed mode with WorkShelf set to "Always On Top when Collapsed" and the Startbar exapnded to full width. When I press my start button it does not bring the startbar to the foreground as desired.

However, when WorkShelf is expanded and I then click on anything in the Startbar, the startbar then overlays the bottom of the WorkShelf.

Is there any option to force WorkShelf to Always On Top when NOT collapsed?

It was a bit hard to visualize what you are trying to accomplish.

Anyway, I assume that the Startbar is always set to 'Normal Z-Order', and that you've enabled the 'Always on Top when collapsed' setting for WorkShelf? Well, try disabling the later setting and, in the Shelf Position section, change 'Show Shelf in Normal Plane' to 'Show Shelf Always on Top'.