Hi Peter,
DTD contains the fares, timetable and routeing guide feeds but the timetable feed only has passenger services and does not contain the additional fixed links or TOC specific interchange.
data.atoc.org contains the TTIS version of the timteable that is passenger services only but does include additional fixed links and TOC specific interchange, however it's version of the fares feed is very old (I think the quarterly refresh).
The fares and timetable feeds have been publicly available from
data.atoc.org for some time. DTD is planned to be opened but not officially open.
Cheers,
Linus