This questioner from Britain asks; Those that live in non-Islamic countries do not have an Imām nor a Jamāʿ ah, so are the Islamic centres that are united upon the methodology of the Salaf considered the Jamāʿ ah?

Shaykh Ṣāliḥ ibn Fawzān al-Fawzān

Oh yes. They refer back to the leader of the Islamic centre and he assumes the position of the one in charge of the affairs of the Muslims in certain duties. He concludes marriage contracts and resolves the affairs of the people. They return to him, as it is equivalent to a small state within a larger non-Muslim state.