We've been through several disasters here in Florida, and the JWs have helped everybody, not only their own. Having said that, yes, they do concentrate and start out helping other JWs affected by the problem, but many others do receive the help as well.
One must understand the resources are limited and the Watchtower does the best they can. Also, at this time of need, the brothers and sisters won't just sit there, they'll start helping themselves and others as well.
The WTBS has received many praises as having one of the most organized ways to help the needy. I've been on both sides, giving help and receiving help, and I'll tell you, it's wonderful.