Q. If the newlyweds join the bris mila seuda (see question above) and they have fulfilled all of the requirements needed (extra food, their own place of honor, their own added people, and nigunim with songs also take place). When it comes to birchas hamazon, since there are two different nuschaos and wording for the beginning of benching, (one for the bris and the other for the sheva brochos), which is the one used?
A. As mentioned above, Horav Shlomo Miller’s Shlit’a opinion is that if a separate table is set for the chosson- kallah, preferably in an adjacent room, and they have their own minyan with ponim chadoshos seating with them, they can recite sheva brochos. Since that is the preferred case they would be reciting their own typical birchas hamazon with its sheva brochos.
If they end up benching together, following the other opinions, the Rov’s suggests that the nusach of the bris milah takes priority for the zimun, since after all they are the main component of this seuda. But after benching, and after the traditional bris horachamos are said, the sheva brochos can be recited.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a