Have you added the code for this font to your external landing page? If not, here is the code to add:
<link href='http://fonts.googleapis.com/css?family=Pontano+Sans' rel='stylesheet' type='text/css'>
Also, try removing the comma after "sans-serif" so it reads: font-family:'Pontano Sans', sans-serif !important;
Corey Bethel
Consultant | Etumos