Okay, then let's run a quick list of things that need to be there for bloom to work:
1) Check that you Mod.ini file is set up properly. The "screenshaders" option should be set to 1, and you should have a "screenshader1" option that's set to "bloom/bloom.fx" or the likes.
2) Make sure the bloom.fx file exists. It will be in your effectbank/bloom/ folder. There should also be the Quad.fx file in your effectbank folder, but we already covered that.
Hmmm... I think that that's all that's needed for bloom to work with PB.
Can you take a screenshot of what your level looks like?
The one and only,
Only those who sow the seeds of their desires will reap their benefits later.
However, I have seeds of my own to tend to. I don't have time to be someone else's watering can.