bundle show: Que versión de una gema estamos usando

[~/Dropbox/src/ruby/sinatra/bootstrap_example(master)]$ cat Gemfile
source 'https://rubygems.org'
gem 'sinatra'
[~/Dropbox/src/ruby/sinatra/bootstrap_example(master)]$ bundle show

Gems included by the bundle:
  * bundler (1.3.5)
  * rack (1.5.2)
  * rack-protection (1.5.0)
  * sinatra (1.4.2)
  * tilt (1.4.1)