It seems that docker from the docker bundle doesn’t include “compose”, and the docker-compose binary is for docker v1, and not v2, which seems to be current and also built into docker. It could be added as a separate package that just drops the latest binary into /usr/lib/docker/cli-plugins, which worked fine when I grabbed a precompiled binary from git.
note that you can skip /usr/local and have the os-managed binary in /usr/lib/docker/cli-plugins or /usr/libexec/docker/cli-plugins to avoid conflict with a user’s /usr/local