The amount of chlorine it would remove varies based on the specific filter and the
water flow rate. Most tap water filters are simply meant to remove taste and
odor.
As for chloramine, an activated carbon filter will not remove it. Removing
chloramine with carbon requires MUCH longer contact times, and even then, it
would only remove the chlorine portion of the chloramine, leaving free
ammonia.
I've got an article on my website about the subject:
http://www.csd.net/~cgadd/aqua/art_chlorine.htm
-- Chuck Gadd