Yes.  The start reclaim command can accept a single TDEV, a range of TDEVs, a device group or a storage group to specify the devices to be reclaimed.  To start a reclaim on all the devices in an SG, the command syntax is as follows  symconfigure -sid xx -cmd "start reclaim on tdev in SG ;" commit  Hope that helps. 
I have used to the symconfigure -cmd "start reclaim on tdev XXXX;" commit command to reclaim space on a single tdev before but now what I would like to do is run a start reclaim on an entire storage group without having to run it on each tdev.  If this is supported I could not find the right syntax for the command.  Anyone know if it is possible and what the syntax is?  If it is not possible I'll list the tdevs and use a loop to issue the start reclaim on each one.
Can you do a "start reclaim" on an entire Storage Group?