2. The RAMACH and the ROSH write that even if all the people at the Se'udas Nesu'in attended the Chupah and heard the seven Berachos, they can still recite the seven Berachos at the Se'udah, because there is a separate obligation for reciting the seven Berachos at the Se'udah.
Who is the RAMACH?
The Ramach that we cited is quoted by the Kesef Mishnah (Hilchos Berachos 2:9).
The Ramach was Rabeinu Moshe bar Me'ir ha'Kohen, one of the leading sages of Provence, who lived during the late 4900's (late 1100's to mid 1200's C.E.). He wrote Hasagos on the Rambam's Mishnah Torah, and the Rambam himself wrote back to him with great respect. Most of this correspondence was destroyed during the Explusion from Spain. We find him quoted by the Ran and Rivash.