Your base is impermeable. However, if you felt your clay was poorly draining I could see a drain system in the subgrade to relieve excessive water percentages. This could be beneficial, but more than likely is not necessary. The important part is making sure your subgrade is the right moisture content before you cover it. If it is too wet you'll just turn your patio into one giant trampoline once you run the compactor and those molecules get nice and lubricated.
The general answer to your question is no, but we do not have pure clay up here either so perhaps some southern guys will be able to provide some more advice.