Having said that - looking on Google Maps (ahem), which uses Translink's Open Data (phew ;) it does look like Translink have made the effort to map routes to individual stands.  However this is not the way they've chosen to do it in the Translink App.  And I notice te data is already a mess (with the 300/300a mapped to more than one stand...) 
I think a single 'bus_stop' tag is the way go!