The answer to that question is a big fat YES!
That is if you have set up your companies Microsoft Exchange Server to receive email on your smartphone. There is a great article about this at Wipeout: When Your Company Kills Your iPhone. It is interesting that your employer can wipe a personal phone without any extra permissions on your part. It is part of the Exchange Server software, actually has been since 2003, when a growing list of smart phones started to come loaded with software from Microsoft that makes remote wipes, and many other remote-control commands possible no matter what.
To verify, I used my iPhone, which I had set up to our Exchange Server a while back to see if I could wipe my iphone. I can and if you would like to see that you have access to it, and your company has Outlook Web Access enabled just follow these instructions:
From a desktop or laptop log into the OWA server to see your email. Click Options and scroll down to Mobile Devices. If you click that you will see your mobile device complete with all the info you would need about your smartphone. You will also see links above your device to remove the device, and wipe the device.
Needless to say, I have removed my device from the Exchange server and I am no longer seeing my emails on my iPhone. This of course brings up a lot of privacy issues, while at the same time I wonder why I even need to read my work email on my personal phone. Some of the reasons I came up with are that it is easier to read the emails on the iphone, I can landscape for even better reading and the internet connection via a browser is significantly faster on the iphone. But, those are just conveniences that I can live without to do my work and read email while I am in the field working.