As said no problem with installing Sonar on second machine. What you can do is update everything on the old one and then just copy the Command Center download folder over to the new computer. Saves a tonne of time and bandwidth, You only really need to download once for every update if you do this.
The folder is found in:
Computer /C / Program Data/ Cakewalk/ Command Center/ Downloads
First install Command Center to the new Computer and log in.
Run CCC and install just Sonar.
Now copy the CCC download folder content to the same location in the new computer.
Now when you run CCC and choose other parts, like Dim Pro, It will install fast as it is already downloaded and ready to install.
You do realise that Sonar expires for updating after a year from when you purchased it. You will have to anti up to get the latest versions if your year is up.