Glad you like it.
You're correct, Tabli is only intended to help you manage windows and tabs within the current browser session on your current machine.
Saved Windows (http://antonycourtney.github.io/tabli/tabli-usage.html#save-...) are stored as bookmark folders so will sync as normal bookmarks and show up when you start Chrome on a different machine. (Currently saved windows are only loaded when Tabli initializes, but that's fixable.)
I don't use Chrome on multiple machines simultaneously so hadn't really considered this use case. Thanks for bringing to my attention, will give it some thought.