Kiko,
sfntly has no text layout or glyph rendering capabilities. It doesn't do any of the web based font access. It's a library for reading the font file and manipulating the font. So, it won't be able to do what you are asking. There are no plans to ever add these features to sfntly.
Could you use the
Google Web Fonts team's API and get the @font-face rule for the font you want, parse that to get the url for the font and the type of the font, stream the font data in, provide that font data to the java.awt.Font class, and then use that Font object in your layout?
Note that sfntly is not from the Google Web Font's team but it is a library used by them to provide their service.
Stuart