Yes, Network capability exists

Installed, network activated and tried on subsite. Worked like it should. Tried on main site and got nothing. Noticed on the subsite, the pointer(box) was now positioned differently and able to run off the top of the page.

Network deactivated and reactivated on main site and subsite individually.
I can now have different pointers on both sites and it doesn’t matter if they point to the same id.

The above I think, proves that it will work on two sites of a network without conflict. It definitely proves that you can’t just make pointers on the main site and have them show on subsites.

When I make more subsites, I’ll try messing with it some more. I only have one on this install. Most people don’t need pointers on their main site so network activating might still work but you just wouldn’t want to try and make any pointers on the main site. The only benefit of network activation would be for networks that already have a lot of subsites. Of course the could use some kind of wp management tool I suppose.

https://wordpress.org/plugins/better-admin-pointers/