Hi Julian!
Are you still in Dublin these days? How are things?
The Epic doesn't have a bolt-on neck, it should have a 'set' neck where the neck is set well into the body and glued.
If all you adjusted was the bridge you might have brought the action down too low, or the neck truss rods might need an adjustment to get rid of the buzz. In some set-ups a little fret-buzz is normal, the question is how much do you want?
It sounds like you are not used to setting up a bass, I'd recommend bringing to a guitar tech and get them to set it up the way YOU want. if you're still in Dublin (assuming you are the Julian Arnold I know) then I could recommend some people who could do that or I might be able to look at it for you (though I'm not very good at set-ups I might be able to point you in the right direction).
Respond and we'll see what can happen.
All the best,
Rob.