Apple iTunes and the Music apps lists some radio broadcasters under it's "Radio" page. Can publishers submit their own streams to be listed there ?
Apple is no longer accepting new submissions for the "Radio" section. See more at itunesinternetradio.com.
Should this change in the future we will update this article.
Listening to streams in the Music app
While it is not possible to submit a stream for syndication, users can still listen to live-streams from iono.fm by using the "Open Stream URL.. ⌘" menu item in their Music app.
Every iono.fm stream has a public page that lists their individual stream URLs.