In some scenarios it might be necessary to know whether a process is actually being redirected or not. A case in point is for example a library that is loaded and needs to know whether the host process and the library have an identical view of the virtualized world. You can use GetTokenInformation with TokenVirtualizationEnabled to find that out.
The same API with TokenElevation instead of TokenVirtualizationEnabled will give you whether you run with an elevated token or not. Note that this does not guarantee you are running as administrator. You might very well be Backup Operator or standard user with a couple of manually added privileges.