All I see is a picture of a via.
You have to reckon this as inductor of 0.2 - 0.5 nH depending on the hole diameter, length and plating thickness. It's bad practice to use them in series with an antenna because of this variability . If you want an earth use many in parallel or eg a fan terrnination over an earth plane.
Keep everything on one layer.
I'll have a look at your link and get back to you.
edit : had a look, and it's irrelevant.. Correction? /edit
You can model this sort of stuff with eg HFSS and Sonnet etc , but the seats aren't cheap. and they're not easy to use.
Allan