As an admin, you will have access to all usage details for each sub-organization as described here. The usage details will include hourly usage across all billable parameters as well as the top 500 custom metrics for each sub-organization. Further detailed usage reports can also be created on request by your account representative.
It is worth noting that each sub-organization you create will be rolled up to a parent account. This relationship will apply solely to billing, however metrics and events will continue to be isolate in their own individual orgs.