Sharing the users with another website is simple.
You have to create a JMS Template rule where you select the "template site" that you want to share and where you go in the "sharing" tabs where you click on the what you want to share.
See for example the video 16 that show how to share the users.
This is the same for any extension that can be shared.
www.jms2win.com/en/tutorial#jms12x-16
To know which extensions can be shared, see the list of extensions defined in the JMS Tool menu
www.jms2win.com/en/list-of-extensions?vi...id=269&Itemid=53