SURE !

We use two (or more) subnets in most of our tsm servers... always best to
have minimal hops.
Our larger clients have multiple interface cards (to multiple subnets)
also...
We run with a production network for user traffic and a backup network (for
backups)
On some of the clients we have to put static routes IF the tsm server isn't
on the same subnet as its tsm server
but things work really well :-)
We've even played with pushing backups across two interfaces from a single
client (to a pair of interfaces on the tsm server)

Dwight