I had the same problem and I just tried using the following as a workaround. Seems to work so far. You can even create a dummy template that just contains references to all those static assets.
{% stylesheets
output='assets/fonts/glyphicons-halflings-regular.ttf'
'bundles/bootstrap/fonts/glyphicons-halflings-regular.ttf'
%}{% endstylesheets %}
Notice the omission of any output which means nothing shows up on the template. When I run assetic:dump the files are copied over to the desired location and the css includes work as expected.