I've been struggling to automate the building of my soundbanks on our build machine and I found this post. I realize it is old but there really isn't much documentation out there on how to automate simple wwise tasks.
After some digging I don't think you can just say Wwise is portable. Our build machine is running Mac OS. On my local machine when I installed 2021.1.10 it installed the files at my chosen location but it also installs a bunch of apparently necessary files inside of the Library/Application Support/Audiokinetic folder. This mucks up my process a bit because it requires sudo permissions to copy files to that location. This isn't access I have by default in my environment. So it has not been a simple "copy the entire Wwise installation directory to your source control" kind of situation. Perhaps it is portable on Windows? but really being able to install everything from an offline installer at the command line (and ideally without needing admin perms) would be much cleaner.