I figured out the issue, at one point I was using the TrueType version of the normal font weight but not the bold. Apparently php-font-lib can only generate the compatible fonts from a ttf file and not woff. When I switched both declarations over to ttf it generated the necessary files and now both weights are working.
JoomDev is not affiliated with or endorsed by Open Source Matters or the Joomla! Project. The Joomla! logo is used under a limited license granted by Open Source Matters the trademark holder in the United States and other countries.