IIS7 cmdlets do not have the parameters for remote machine connection. You should use Powershell remoting.
Here is the example of using the latest Powershell version's remoting, remote machine name is jhkim-vm2k8-x86 in this example and both local and remote machine should have IIS powershell provider and the latest powershell version:
PS IIS:\> enter-pssession jhkim-vm2k8-x86
[jhkim-vm2k8-x86]: PS IIS:\> dir Name
----
Sites
AppPools
SslBindings
[jhkim-vm2k8-x86]: PS IIS:\> cd sites
[jhkim-vm2k8-x86]: PS IIS:\Sites> dir
Name ID State Physical Path Bindings
---- -- ----- ------------- --------
Default Web Site 1 Started %SystemDrive%\inetpub\wwwroot http *:80:
[jhkim-vm2k8-x86]: PS IIS:\Sites> Stop-WebItem '.\Default Web Site'
[jhkim-vm2k8-x86]: PS IIS:\Sites> dir
Name ID State Physical Path Bindings
---- -- ----- ------------- --------
Default Web Site 1 Stopped %SystemDrive%\inetpub\wwwroot http *:80:
[jhkim-vm2k8-x86]: PS IIS:\Sites> Start-WebItem '.\Default Web Site'
[jhkim-vm2k8-x86]: PS IIS:\Sites> dir
Name ID State Physical Path Bindings
---- -- ----- ------------- --------
Default Web Site 1 Started %SystemDrive%\inetpub\wwwroot http *:80: