There’s some info in this thread that should help with what you’re after. For the Grid class itself you might find it easier network wise to have it as an in-scene network object.
You might also want to look at spawning network objects per location or for bombs at least. I attached some code I was playing with, the way it sets initial network variable values is very dubious but it might give you some ideas.
bomberobjects.unitypackage (7.6 KB)