Can Halion be put on one machine and Halion SE on a separate machine, with the one license?
I may be wrong but Halion SE is apparently to be released free of any cost anyway - so… yes.
…and I know why you ask. I guess you had the same idea as me. 
The HSSE license is part of the Cubase license. So they’re not at all linked.
Okay, so I guess I meant Halion Sonic?