I can’t help much, but this isn’t really the correct forum for such a
discussion anyway. My suggestion is that you search for how to
configure the gem command to make use of a proxy. Bundler should use
those same settings under the covers when it’s installing gems.
You may also find specific information about using proxies with bundler
itself, so take a look around if you haven’t already.
Finally, there is probably some sort of forum where the bundler folks
hang out. I’m not sure where that is offhand, but you should be able to
dig it up with a little effort.