vermiculite

vermiculite is usually used to retain moisture in soil. Get perlite.

 

Perlite aerates soils my friend ... and should use 20% of it as your mixture...

 

Vermiculite does airate soil and of course too helps retain moisture but the answer is yes it does but in a different way to perlite which makes it easier for air to make its way into the soil where as verm retains air itself as well as lots of micro nutrients plants need.

Here is a good guide on vermiculite I found detailing uses etc
http://vermiculite.org/Downloads/TVA-R001.pdf