I can make the suggestion to the team, but I do see some conflicting possibilities here. Particularly as it stands you gain 1 culture point per turn per capital city for your civ (you can gain more by defeating or taking over enemies), and other bursts or increases tend to be only one time rather than recurring
Unless they've been removed from the game, the Galactic Achievements (colony improvements) "Galactic Commission" gives you 3 extra culture points per turn, and "Cultural Beacon" give you one extra culture point each turn.
"Hall of Tradition" (from Sacred History on Traditionalism Ideology tree) is a Civilization Achievement that gives you one extra culture point per turn.