IIRC, the feat as worded only functions with two-weapon fighters, but in my campaign we house ruled it to be allowed for two-handed weapon fighters as well. Normally you could where a buckler and wield a two-handed weapon at the same time but you could not gain the AC bonus of the shield if you were attacking with the two-handed weapon. Again this is all as far as I know off the top of my head, since I don't have my stuff with me at the moment.
Hope it helped though
Drexes