It does work after a fashion. Press the home button to invoke Siri, and you get what appears to be an call from your own number. Now you can use Siri commands as normal. When connected this way Siri does tend to stop listening rather abrubtly.
For making calls its probably quicker to use the SYNC voice dialling. You are have a little less flexibility of how to specify who to call but it works fine once you train yourself what to say.