A few suggested changes:

Cameraderie- When you cast a spell using a spell slot of 1st level or above that charms a creature, the target and you gain temporary hit points equal to your proficiency bonus plus twice the spell slot level. When the spell ends, if the target still has these temporary hit points, if the spell would inform the creature it was charmed it instead does not.

1: It is "using a spell slot" instead of "a spell of". This makes it clear that if you (say) can at-will cast a 3rd level charm spell, it doesn't grant temporary HP.

2: I added 2* spell slot level to the temporary HP. I might even strip the proficiency bonus. Make the gain proportional to the cost.

3: "It doesn't know" becomes "it is not informed". I think this is your meaning: if the creature was told it was charmed in the original version, it would suddenly forget. I just want to remove the "the creature knows it was charmed" from the spell you modify.

I guess this makes something like domination questionable. When you dominate a creature, should they become aware that they where a puppet?