My wife runs a community choir with some friends in a notional elected committee. Is buying the committee a token yearly thank you like buying gifts for a boss too?

It seems to me, at best, the HOA is a committee of volunteers from the community, serving the community. It is not your boss; it's your peers completing the executive function of the rules and procedures you have collectively agreed.

Buying a gift for a peer's uncompensated labour is standard politeness.