Making a Camera (Bloom) Effect Appear behind UI

I'm working on creating a kit of assets to make UI forms with. One of the thing I'm using is HDR Bloom (The component in the 5.x standard assets) on a camera with a really fancy lens flare. This allows me to hover over a button and reflect the change of color into the effect. I won't lie it looks shiny. There's one thing I would like to change, and that's placing the effect to be behind the UI elements (which are translucent). The UI is Three Dimensional as well.

I was thinking this might be possible if I can super impose one camera on another post processing - simply moving my bloom components to the secondary camera and then cull everything else. The confusion on this idea is will I still get the same effect when colors change in the UI, and how would I actually go about doing it? Also, is there a better way to go about it?