modelwire.com is a platform that many agencies use to send model packages to photographers and clients. You can register as a photographer and then send permission requests to agencies so you can view their boards and you can message the bookers through the system.
Modelwirenetwork.com is a place for freelance models, MUA's, stylists and photographers to meet, similar to here on MM.
Same company owns them but they are two different platforms. Unless you're shooting for the agencies a lot or booking models for clients already modelwire.com wont be of much use. It's really a booking platform and not a networking platform like modelwirenetwork.com. But the traffic and volume on the network site is very minimal.