Mostly on 4 wheeled/footed Mobs. You wil see it on the 4 foot Demons in the Legion pre-events.
But a simpler test is in Ulduar at the Flame Leviathan. Start a cat druid with a fighclass from Bettersister or Drwolf. Both use Wild Charge. They try to use the spell in a range between 8-25 yards (I've changed it to 10, but this will also not work). You will get the ingame message "too near". At the moment the Flame leviathan is not killable as a cat druid with this fightclasses (due to the wrong range calculation)