Hmm good question. It seems clicking on the podcast name just always takes you to the most recent episode on the mobile site.
If you know the name you should still be able to find it using search. If you are on android you could try the "Giant Bomb Beta" app by bitwrit (not sure if there is an iphone version). I believe it will show all bombcast episodes but I don't think it lists the other podcasts on the site. Using your favorite RSS reader of choice might be the easiest solution.
And some browsers will let you request the desktop version of the site (sometimes called changing user agent) which may work also.