What is halacha l’maseh by a Bris on Shabbos for the one making the brachos over a cos of wine. Are they yotzee with this kiddush? When should they drink from the cos if at all? Afterwards should they hear Kiddush from someone else or may they make themselves?
Kiddush on Shabbos morning involves nothing more than the borei peri ha-gafen blessing. The verses we say before are customary, but not obligatory.
Therefore, even though Shabbos is not mentioned, the person making the berachos is yotzei the obligation of kiddush with the blessing, and he should eat some mezonos afterwards, to ensure that it should be kiddush be-makom se’udah.
Although he thus fulfills his obligation of making kiddush, he can still make kiddush again later for others, and this is perfrectly fine.