Technically there are two solutions here
Point to Point + Dublin city buses (its not just Dublin Bus...)
Point to Point + Luas
Thats complex as its a new ticket type which needs to be understood by a lot of hardware
The easy solution is to load two separate tickets onto the card, Leap card allows for at least 5 if not more 'products' to be loaded at the same time
Point to Point + Dublin Bus Annual
Requires no IT changes on the ground just some minor admin at the IE office end when issuing the tickets.