I'm assuming the part in parenthesis is for our benefit and not part of the name? If so, you are fine.

Instance names must be unique on a Windows host. On a network, the hostname\instancename must be unique. These two are unique

WIDSQL04\ProjectWise

WIPSQL04\ProjectWise

Because the hostname is different.

Put another way, I can have a "Sales" instance on every windows machine on my network.