If you want to deploy Citrix XenApp on a VMWare hypervisor then you should read the guide provided by VMWare.
This guide provides best practice guidelines for deploying Citrix XenApp on VMware. The recommendations are not specific to any particular set of hardware or to the size and scope of any particular XenApp implementation. The design examples and considerations provide guidance only and do not represent strict design requirements. Flexibility in Citrix XenApp deployments combined with the flexibility of deploying on vSphere allows for a wide variety of valid configurations.
So download your copy now and read this guide.