Yes, ENVY (aka ENVY/Developer) is a part of of VA Smalltalk. You can read about it in our online documentation - Smalltalk User's Guide
I'm probably not the best person to talk about VW Store, but my understanding is that it is based on an optimistic checkout model of the repository (meaning that whatever you checkout is not locked and may change before you check it back in). Because this model deals in large-grained artifacts, it is well-suited to developing over a WAN or other network with large latencies.
ENVY/Manager is based on a directly connected model of the repository (either local or remote), so you can always see the latest updates. Because this model deals in fine-grained artifacts, it is better-suited for a LAN network with small latencies. You can use it over a WAN if the network latency isn't too large, but this environment is better served with scheduled replication of the repository and importing of artifacts from a local repository into the main repository.
John O'Keefe [|], Principal Smalltalk Architect, Instantiations Inc.