Been to Boma many times, LOVE it. Never been to Tusker House, but it seems to be kinda ... Boma-ish? Would the two restaurants be too similar to really enjoy on the same day (Tusker House lunch / Boma dinner)?
Boma is about food, Tusker House is about Characters & convenience.
Unless they've added Characters to Boma, the meals are entirely different.
If you mean that both meals include the countless combinations of curry served with the diversity of a buffet, then OK, they're similar.
For my family, Boma is not worth the special journey (using Disney transportation) for either dinner or breakfast - particularly if we had enjoyed a Character meal at Tusker House that gives River of Lights tickets. Sanaa, with a daylight view of the Savannah, is worth the journey. We can get reasonable curry-food where we live.
But when we stayed at AKLodge, Boma for breakfast was a 'standout' meal for us, and Tusker House would be the place we might eat (that also happened to use curry in their seasonings) to get River of Lights tickets & pictures with some Characters.
But Boma could be a destination for breakfast if someone really wants something that is 'different' and/or that is marginally-better for food than Tusker House when comparing the two. Also, AKLodge is Disney's best themed resort and worth a journey, particularly if you have a no-Park day (that avoids shopping in Disney Springs).