Have you run this same script manually on a wireless computer, using the exact same commands? Does it work?
You can validate the network connection, it all depends how you want to do this. Here's an example that maps a drive and provides the credentials (not incredibly secure) and then checks to make sure the directory exists before proceeding.
net use z: /delete
net use z: \\server.domain.com\share\software\ password /USER:domain\username
IF EXIST Z:\AltirisInstall GOTO ismapped ELSE GOTO isnotmapped
:isnotmapped
SET ERRORLEVEL=123
EXIT
:ismapped
(proceed with script)