$9.99 App plays Sirius on the iPhone now

And it works

http://www.normsoft.com/kb/idx/55/292/article/

Can I play Sirius Satellite Radio on Pocket Tunes Radio?
- This article Applies to the Apple iPhone and/or iPod Touch only -

As of version 5.2 of Pocket Tunes Radio, you can play Sirius Internet Radio. We added support for Web-based stations and this allows you to play stations that normally require you to be using a PC rather than a mobile device.

Here are the steps to do that:.......... (see link)