The French ue a mixture of trains and buses ... I suspect Lee may be able to tell us if there's a useful model there.
Whilst there are numerous examples of routes with combined bus and rail timetables across France, in Brittany where I am, the way the overall network has been co-ordinated has seen a decline in this way of doing things in favour of routes that are either all-rail or all-bus.
Currently we have one route that has a permanently combined bus and rail timetable:
Quimper-BrestWe also have 2 routes that currently have combined bus and rail timetables while they await officially confirmed line renovation work:
Dol-Dinan-St BrieucRennes-Janze-ChateaubriantThe rest are either one or the other.
In terms of integrated bus/rail ticketing, we have the Uzuel+ range, available in weekly or monthly versions, which combines unlimited train travel (this can be on TER local trains only or both TER and
TGV▸ express trains depending on your ticket option choice) between 2 points (eg Callac-Rennes) with unlimited travel on an urban public transport network of your choice from the following - Brest, Morlaix, Landerneau, Lannion, St Brieuc, Lorient, Vannes, Pontivy, Quimperlé, Quimper, Rennes or St Malo. You get up to 75% discount compared to normal fares, and your employer can cover up to 50% of the cost. Also, those bus services that are classed as equivalent to rail services (such as St Brieuc-Loudeac-Pontivy-Vannes/Lorient or Pontivy-Rennes) count as actual rail services for the purpose of this ticket range.
There are also specific bus/rail integrated tickets for the Rennes area, for the Rennes-Janze-Retiers route, and for the Brest-Quimper route.
There is also a network of rural/interurban bus services that dont have integrated ticketing with rail. However as a standalone add-on they can provide excellent value as they are dirt cheap at a flat single fare of 2 euros, including a change/connection if its made within an hour of initial validation, on routes that can be as long as Carhaix-Brest, Carhaix-Lorient, Carhaix-Morlaix and Carhaix-Loudeac to name a few examples from my neck of the woods. The exception is Morlaix-Roscoff where you can take advantage of the 2 euros fare AND/OR have through ticketing from the rail network.
Finally, where I specifically am in Callac, we have around 5 trains each way per weekday to Guingamp and Carhaix, but no regular bus services. However, we do have a transport on demand service that operates on Monday-Saturday and will pick you up and either drop you off in the town centre or at the railway station to connect with trains. This has a flat fare of 2 euros, which may not sound like great value compared to the same price for rural/interurban bus services, but is still execellent value compared to taxis, which are very expensive round these parts.