Lacking any sharp, I will venture a guess which normally gets stomped on later by the real shapies. A lot of units did not receive pay after 1863 and some even earlier. Many begged for support from home. The Indians in units that were mixed, probably fared as their compatriots. Those in pure Indian Units may have victums of a bad system. First their leaders knew they could exist without pay, where other whites and blacks starved to death. Second I would imagine there were some who took advantage of the system. Third, I doubt the Indians complained. They had never been payed to fight wars before, unless we count the French. Many went to fight, because of friends, and some fought for the protection of their land and some cases their Nation. Is it right, NO! Did it happen, we know it did. Did the South and for that did the North pay or not pay their Indians on purpose, because they could get away with it. I bet we will never find it in writing.
I had to stop ande look up the last pay of my kin. It was 31 Oct 1863. After that Sul Ross Took command of the Texas Cavalry Brigade, and would try to get something for his troops or dig in his own pocket. Needless to say he was broke at the end of the war. From May 1864 to May 1865 my kin were not paid, and seldom fed. They were in the Atlanta and Tennessee campaigns and all did with what they could find and occasional spoils of war when they surprised a supply train, etc. When the Union captured their supply train, there was no food.
I suspect that pay was not a consideration for the pure Indian units. They probably received supplies when available and had to find their own food. Fare? I don't feel that anything was ever fair in the Indian favor unless it was Audie Murphy or Alan Ladd in one of their movies. That means it may have never happened.