Microsoft have recently clarified the licencing of Office 365 in VDI environments.
You can use Office 365 using dedicated virtual desktop infrastructure but the virtual machine must be dedicated to the user.
in order to install Office Pro Plus 2013 in the Remote Desktop Services (RDS) mode, you MUST have a volume licensing agreement.
Click-to-run supports the full client installation on physical PCs. It also supports the dedicated virtual desktop infrastructure (VDI) deployment on user-dedicated Windows 7 and Windows Server 2008 R2 operating systems or newer virtual machines without the Remote Desktop Services (RDS) role enabled.
Product Use Rights document (PUR).
Microsoft have stated:
“RDS Use Rights are only included with Office 365 purchased via a VL Agreement such as Open. We are currently working on a solution that would be available to customers who are not purchasing Office 365 through a VL Agreement ”
Just to summarise: There are two authoritative documents that state Office 365 Pro Plus (with Click-to-Run) is supported in in “dedicated” VDI environments
Please see the following links: