Oh, if you just want to talk about "is it a bug" I would say "No". The value from the field is transcluded and rendered as a wiki-link, which is just what you would expect.
Use "inspect element" in your browser and you'll see that the code is rendered as:
So there's a link inside a link. The inside link wins, just as it would if you made the HTML by hand.
In general, when transcluding text, you want the text to be rendered as wikitext. In most cases you would be disappointed if it did not render as wiki-text. In the case of JeremyRuston, if you didn't want it to render as wikitext, you could precede it with a ~, e.g. ~JeremyRuston , just like you would do if his name appeared in a tiddler.
-- Mark