list applied Irules for a specified VIP

In that case, you could use Putty's

Plink.exe

tmsh

$f5Host     = "f5.example.com";
$f5Cred     = (Get-Credential);
$plinkPath  = 'c:\PATH\TO\plink.exe';
$vip        = "MY_VIP_NAME";  Or blank for all VIPs
$tCmd       = "tmsh list ltm virtual $vip rules";
$command    = "& `"$plinkPath`" -l ""{0}"" -pw ""{1}"" {2} ""{3}""" -f @($f5Cred.Username, $f5Cred.GetNetworkCredential().Password, $f5Host, $tCmd);
$response   = Invoke-Expression $command;
$response;

You'll will have to parse the response to get the data in a more usable format, however.

You could also use the older SOAP based iControl, but I don't have an example for that one.