You can use the below cmdlets to Connect to 21Vianet Hosted Office365 Environment.

Open PowerShell in Elevated Mode and run the following commands,

Set-ExecutionPolicy -ExecutionPolicy unrestricted

$UserCredential = Get-Credential

$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://partner.outlook.cn/PowerShell -Credential $UserCredential -Authentication Basic -AllowRedirection

Import-PSSession $Session -DisableNameChecking

You can see now it is connected. You can run the Cmdlets for Exchange Online and validate.