As soon as a Template has been connected to ProjectPlace it becomes visible for all members of your account in ProjectPlace and they can create new Workspaces based on that template. You can hide the connected Template from non administration staff if you want to.
Go to Workspace templates in ProjectPlace.
Select a connected Template.
In the details pane on the right hand side, toggle the option to Hide from non administrators.
Account administrators and administrators of that Template will be unaffected by this change while normal account members will NOT be able to find the template and will not be able to create new Workspaces based upon it.
Details pane of a connected template in ProjectPlace