No. Global Load Balancing is a combination of Load Balancing across widely separated physical locations, together with modifying DNS entries. Zeus Load Balancer does not control any aspects of DNS by itself.
There are no intrinsic limits on the distance that pairs of Zeus Load Balancers may be located from each other. However, they must both be on the same ethernet segment. That is, ARP packets sent by each Load Balancer must reach the other Load Balancer. In general, there should be no routers between the two balancers.