Under the routing setting, I've switched it to 10.0.0.0/16 - which then provides a route of
10.0.0.0 10.0.1.1 255.255.0.0 UG 101 0 0 tun1
10.0.1.0 0.0.0.0 255.255.255.0 U 0 0 0 tun1
which still doesn't allow a connection (I'm trying to ssh to another machine with a private IP address).