I don’t know anything about PouchDB’s replicator implementation.
I would assume it sends _bulk_docs when pushing, since that request is a standard part of the protocol.
I don’t know if it uses _bulk_get. We invented _bulk_get for Sync Gateway; the spec is documented, but I don’t know if CouchDB has implemented it, or whether PouchDB sends it.
The easiest way to test would be to use something like Charles Proxy or HTTPScoop to sniff the HTTP traffic from PouchDB.
—Jens