The Vimeo videos will be added to the PX guide as iframe elements. For PX to track any actions within an iframe, the PX tag would need to be added to the iframe content, i.e. the iframe ‘src’ needs the PX tag installed. This is not supported by the Vimeo platform as far as I know.
I know Vimeo does support Google Analytics. In theory, you could set a ‘referrer’ or other event metadata that would be unique to the playback events from the PX guide. Then those events could be tracked via GA. Unfortunately, I don’t know of a similar workaround for PX.
We embed YouTube videos in guides and dialogs. We don’t track the views from Gainsight; in YouTube, we look for the traffic source coming from our web application domain.