Hi Kathleen,
Another option if you are looking to connect to other systems as well is to use a standardized back end interoperability tool like XchangeCore, formerly UICDS. It is free for public entities through DHS and, actually, you are in good shape in CA as CalOES has done a lot of this work already by integrating ArcGIS Online. Check in with Jim Morentz (morentzj@leidos.com). I'm not sure of the status of the WebEOC adapter, but I have heard of projects connecting WebEOC, eTeams & DisasterLAN systems across multiple states.
Cheers,
Scott
NJ OHSP