The referenced article implicitly describes the "bundle" in this paragraph:
For decades, people watched television one way: through a boxy contraption, tied to a schedule set by broadcasters. It was all supported by advertisers and beamed free over the airwaves.
The bundle is the combination of the television, the shows, and the schedule that defined when shows could be watched.
VCRs began breaking apart the combination (unbundling) by making it possible to watch the shows on the television on a schedule of the viewer's choosing. Companies like Hulu contribute to further unbundling by allowing viewers to watch the shows on a computer instead of a television.