What is the different between Docker bundles and docker-compose?

The main different is that docker bundle is oriented to be used this the new server side orchestration features it use the docker service internal flow.

docker compose has all logics client side because it the client (compose) that do different requests at the server (daemon).

For docker bundle all flow is managed by the engine.

A Dockerfile can be built into an image, and containers can be created from that image.

Similarly, a docker-compose.yml can be built into a distributed application bundle(DAB), and stacks can be created from that bundle.

In that sense, the bundle is a multi-services distributable image format.

Source: https://docs.docker.com/v18.03/compose/bundles/