Bomb making instructions are generally protected speech.

Distributing such instructions with the intent to further a crime makes the speech unprotected. But, each element (e.g, knowingly intending to further a crime, and so on) has to be proven in a court of law to strip the speech of its protected status.

From the statute you linked: "...with the intent that the teaching, demonstration, or information be used for, or in furtherance of, an activity that constitutes a Federal crime of violence;"

edit: typos