I have found these podcasts in iTunes and could subscribe to them. It was also possible to download episodes. But I have done this test with the itunes software on my desktop computer. I have no mobile device from Apple. That is why I can't tell why it does not work with the iPhone.
But it should work with the iPhone too. Your feeds are valid and contain all necessary information. podPress seems to work very well in your blog as far as I can tell.
Are you getting error messages?
BTW: It looks like your theme does not load the podPress scripts. It seems possible that it does not use the common Action and Filter Hooks to include them automatically.
That is why there are no players in your posts with a podcast episode.