@JTT,
"bonding" as used by electricians colloquially is the action
"bonded" as used by electricians colloquially is the result
"bonding" as referenced by the Code's strict legal definition is the result
As to manufactured mufti-ganged boxes versus field assembled multi-ganged boxes no bond is usually needed for the former, and a bond is usually needed for the latter, however for the latter that does not necessarily mean a separate bonding conductor.
It also depends on the type of junction boxes used and how they connect to each other mechanically such as EMT tubing or rigid pipe for example.
Most people most of the time think that residential wiring is the net reality for most electricians, I've never even wired a house and would not consider myself an expert in residential wiring, I'm an industrial guy.