Yes, its easy and at the time of breaking a Guild the Guild Bound items can be found at Guild Leader's inventory and Guild Storage(when a player leaves guild who's having Guild Bound items, the items will be transferred directly into the Guild Storage)
http://rathena.org/board/topic/95205-request-script-to-counter-bugsexploits/?p=260188
Skorm had made onguildbreak.patch, ill test it again to confirm how it actually works.
@Ako si Ranz I agree, but its tough since Bound takes 1 slot. But, we can expect the cards to keep the bound if it works like what Lighta said!