Mine didn't come with a rubber mount & bolt either.
What I did was used the rubber mounts from the stock airbox.
I used one, and a half of another one. (I cut a 2nd one in half).
I stacked them together on a 6mm bolt. (the bolt is about 2.5 inches long). It works just fine holding the tube up. It doesn't fit flush mind you, but neither do the bolt and rubber mount that the AEM kit comes with.
As long as it provides some kind of support then it's fine.