Wall Street and Oxford usually both go into my Buro Capital. I frequently find that the settled GAs start to stack up.
Additionally, some Combos that I'm fond of are West Point+Heroic Epic. After Pentagon, and maybe some help with Barracks/Drydock/Vassalage/Theocracy, you can churn out some dangerous super soldiers.
Also, West Point+Red Cross if West Point was previously deferred for a while. Prior to Mechanized infantry/SEALS, the Marching Orders are pretty rad.
I don't know why, but I find myself smashing Hermitage together with National Epic in a wonderspam city. They don't synergize so much as they both exploit wonder benefits. Going for cultural victory, the Artist side of NE is really beneficial, too. I don't think Globe synergizes very well with either of them, except in the case of a SE city, Globe + NE, but since you typically won't have the hammers for Globe quickly, for me this more often than not requires an extra GE that I would rather keep for other stuff.