I’d have to go double check myself to be sure, but if you just have it as heating over the entire region and there are no particle filters, then neutron and all photon heating should be accounted for in the heating score.
The specific tally to separate between neutron and gamma heating would be to use particle filters
https://docs.openmc.org/en/stable/io_formats/tallies.html
If trying to get gamma heating, then make sure to sum photon, electron and positron.
There is also nuance
Both tallies (neutron and gamma dose) should be normalized by the same factor. It would be very unique, niche problems where you don’t.
The normalization constant is the number of source particles per second (n/s, (n+p)/s, etc.) (assuming you are using a fixed source, fusion type calculation)
Typically even if your source was 1000 neutrons/second, this should be your normalization constant for the gamma tally
https://docs.openmc.org/en/stable/usersguide/tallies.html?highlight=scores#scores
https://docs.openmc.org/en/stable/methods/energy_deposition.html#methods-heating