2 Public address routing to different ports of Application Server

Route domains have 2 main use cases;-

• overlapping address space
• separation of security zones in such a way as to prevent 'accidental' crossing of the streams (like someone configuring a forwarding virtual with a destination of "cust a" enabled on a "cust b" self IP).

It's up to you whether separation of test and production traffic warrants a route domain, in fact there may be cases where it would be useful to point a test VIP at a prod server and a route domain may inhibit this.