It appears they only one SalesForce connector can be run at a time. If you preview a model from Designer and there are no SF connections in Teiid, it works. When you create a DS for the VDB and deploy, the VDB cannot get connections from SalesForce. If you delete the preview VDB and Datasource, then the deployed VDB begins working.
I originally suspected that the problem might be that we are running out of connections; SalesForce limits you to 5 simultaneous connections per username/password. But I deployed the two DataSources with different credentials, and the result did not change. Need to investigate more.
Think that we do need to default the SF DS to a pool of 1 and then doc that it should be bumped to 5 for production. The current default is 10, and that should never be. Even 5 will exhaust the limit with just a preview connection.