There are two great anomalies in Sephardic p'sak re: saying brachot that are not in consonance with the Talmud:
- Hallel in Shul on the first night of Passover is said WITH a brachah!
- Hadlakat Nerot Hanukkah is done in shul with a bracha.
In the latter case, the Shulchan Aruch gives the reason as "Pirsumei Nisa." Howver the Talmud's paradigm is strictly ner, ish uveito, and a synagogue fails this paradigm. This is quite an anomaly! However, the pirsumei Nissa model could be used to explain the brachot for BOTH Lighting Candles and Hallel; and this is indeed the Gra's approach.
Conversely, when it comes to saying Kiddush on Shabbat on Friday night IN SHUL, the Shulchan Aruch recommends better NOT TO -despite the fact that this custom has a Talmudic pedigree!
Were you to pose the answer of lighting candles on Hanukkah in shul for guests - this argument would be weakened by the anti-Kiddush decision which pre-supposes that we no longer house guests in shul anymore!
I have a novel approach to the 3 cases of kiddush, Hallel, and Neirot Hanukkah based upon a Tosefta in Pesachim. I spoke this out last week Friday night at the Minyan at Care-One in Teaneck. Anyone in cyber-space willing to venture a guess?