No, I'm using two separate vertical and horizontal blurs that are applied to a scene which only contains the bright areas of the screen (with an emphasis on red>yellow>green colors). It's self written and probably not the best/ cheapest way to achieve a bloom, but I think it looks ok/ pretty good.

I've never written a Gaussian blur before but I think I understand its principle. Let's say I implement this blur technique, would you apply it to the whole screen in one stage or would you extract the bright colors, blur it while working on half the screen size and add the result in a final stage (as I do right now)? Is the Gaussian blur worth the effort?