Since the version of Apple iOS 4.2, Mobile Safari in the iPhone and iPad support real fonts in TrueType and OpenType format. The previous version of iOS had to use SVG fonts when using @font-face feature.
Typotheque webfont system supports both SVG and TrueType fonts, to guarantee consistent rendering of webpages in mobile devices, so webfonts will show just fine on your iPad and iPhone regardless of which version of the iOS you use.