Yes, Connections is WordPress Multisite compatible. However, Connections is not compatible with network activation. You should only activate Connections on the subsites in which you intend to use Connections on.
If you have activated Connections for the network, you have to disable the network activation. Then go into the multisite settings and check the box for plugin administration. Next go into individual sites you wish to use Connections, you can then choose which non-network activated plugins you want to activate. Connections should show up in this list, activate it.