Currently there are two options for using this.
1) Build out a tracking layer using pre-defined templates in ArcGIS Online
2) Download the template and deploy it for use in Portal
There should be an option to accomplish this using a service hosted on an organizations backend. You can download the package for use in Portal and deploy it based on the document at http://www.arcgis.com/home/item.html?id=051146f34aec4ef8ac228b5e6b2b8eac but only up through step #8. The process in step #8 is not available from a service fed from an organizations ArcServer's and therefore enabling the tracking can't be completed.
This should offer the same capabilties that are found in step #5 & 6 in this document under the "Add the tracking layer to your map " section
The primary concerns with using the AGO hosted option for us would be spiralling out of control costs. With a Collector solution deployed at the Enterprise Level to over 500 users the data can grow very big very quickly.