Hi Remko,
You can use the Pulseway Manager app -> Manage Devices to define access policies for each device.
In this way you can block the access on certain systems from specific mobile devices.
With an Enterprise Server, this can also be done by creating user accounts and grant access to only certain systems that are monitored using a system account - this can be done using the Associated Accounts feature.
You can find more info about these two methods in this blog:
http://www.pulseway.com/blog/configuring-mobile-device-access-policies-and-user-accounts
Hope this helps.
Best Regards,
Marius