Thanks @supernovia that was helpful.
It took me to a plug-in that defeats the RSS. Apparently Google decided to use this “redundant” RSS link feature to validate the connection between a feed and a web site and have quite strict rules, only permitting one instance of
<link rel=”alternate” type=”application/rss+xml”
on the site and this should point at the feed for the podcast episodes.
I think I’ll try a more general question elsewhere as wordpress defaults to putting two of these on every site.