Taxonomy per-node theming
This is the listing page for the taxonomy items, correct? the node page would be after you click on one of these to see the full content of that particular piece of content? And, if I understand correctly, you want a two column layout of this list? Here is a site I did recently that does that very thing.

http://noboribetsu-spa.jp/en/stay

This is very easy to accomplish. Just float left the class that wraps the item and all of them will fall into place. Let me know if I am not understanding what you are asking.