RSS feed not able to be bookmarked in Safari

Although the RSS feed is viewable in both Safari and Firefox, and is able to be subscribed to in Firefox, I am not getting the familiar “Add Bookmark…” link under “Actions” in Safari. Is there something I must change about the RSS feed or the way I’m posting in order for this to work? Other RSS feeds (such as the one for this site/blog) work just fine…

https://www.ironthrones.com is the site.

Thanks!

-steve.h