Within a term session, it remembers the without option. If you first ran
bundle install --without development
it remembers that you did this and will automatically repeat this for the next
bundle install #remembers and includes --without development
running something else, like bundle install --without nothing should clear the cache. Am I right?
update 20150214: This is fixed in bundler 2.0, according to issue referenced in comment by @Stan Bondi (https://github.com/bundler/bundler/issues/2862). Thanks Stan.