Impossible to tell without more information about the world.
Cannibalism is typically considered a human on human crime, adding into the mix other sentient species has the potential to change that. But how that changes entirely depends on the situation / world composition.
If the world is made up of multiracial nations or federations of nations where there is some degree of equality, cultural exchange, religious parity, or racial origins then yes cannibalism would likely include all sentient species and not just your own. This situation is one in which the species can relate to one another either through religious and cultural ties or they all descended from a common ancestry, and there is no real racism.
If the above situation does not hold true, and the world is fractured into incompatible cultures, religions, and states, then cannibalism is likely species dependent. After all, a human eating a dirty elf may be gross but it is not like they are actually eating a real person.
The ability to cross breed opens up interesting possibilities, but it really depends on what results from that union and how said progeny is perceived. If a human male impregnates a dwarf, is the child a mix, a dwarf, or a human? If the child is a mix is it a distinct race or is it just a mix and eventually you end up with MongrelFolk?
If the child is a dwarf or a distinct race, I believe it really comes down to the first 2 situations. The ability to interbreed likely does not make a whole lot of difference. In Situation 2, sure you have a dwarf son but he is just a dirty dwarf. His mother is little more than livestock you use for fun. In Situation 1, he would have a higher degree of acceptance, which would be influenced by and in turn influence the culture. So cannibalism's definition would likely start from interbreeding sentients and potentially spread to all sentient beings.
If the child is a human, it still relies on the 2 situations. Whether the mother is breeding stock or considered equal factors in. Although the ability to bear human children probably wouldn't hurt dwarves' case.
If the child spirals towards MongrelFolk, it is still dependant on the 2 situations, but the child likely hurts the case for equality in cannabalism. This child would likely be the one most likely to be perceived as an abomination from an alien species.
Ultimately, it comes down to how the other races are perceived, social equality, and societal views. The more aligned and equal the races, the more likely cannibalism crosses species.