I'm pretty sure it'll support infrastructure... I haven't asked the specific question of them, but the specs sure make it sounds like it's a full blown router with a DHCP server. There are references to your "group" being able to work through it, NAT, VPN pass-through, etc. All that could be just with ad-hoc support on the front end, but I dunno why they'd go to those lengths without supporting infrastructure.
ref:
http://cradlepoint.com/phs300/phs300overview.php
http://cradlepoint.com/phs300/ds_PHS300.pdf (pdf link)