Bristle worms are beneficial scavengers. There has been some debate whether they are good or bad, but the general thought is they are beneficial. Ive never had a problem with them.
Most wrasses do not eat them, especially not when that big.
If you have a lot, it prob means your over feeding.
I would take the large ones out as they look for larger food sources. They dont really go for fish but have been known to nip and harass sleeping fish. The small ones are detritus eaters and are fine. When in doubt get it out!