SNZ I tend to follow a specific build pattern with my temples for the Romans.

Julii
Ceres -I build this temple in Segesta and Caralis first. Any others are on an as needed (for the population bonus) basis. The fruitful trait means that if you can give it to the starting sons of your faction leader the Julii will have generals out the ass in the mid and late game.

Bacchus -I avoid this temple like the plauge. The happiness bonus isn't worth the drinking, gambling, and skirt chasing/beastiality/incest/homosexual traits that a general will (not might) end up with. If i build it it's only on the island of great britain, maybe Iuvavum.

Jupiter -This is the main temple i build if there is no genuine need for the happiness of Bacchus or the population growth of Ceres this is what I build.

Scipii
Saturn -This is my Scipii main temple. The law bonus and the law traits make it a good temple to propegate as widely as possible.

Neptune -I save this for Capua, Caralis, and Palma. This where in the fullness of time the Scipii navy of doom will launch from, it consists of 2 Decere's 4 corvus quiquremes and 14 triremes.

Vulcan -I reseve this temple for good troop producing areas. A good troop producing area is a place with 3 or more cities in 1 turns march of each other so you can build an army quickly. Some examples are Fortress Scipii (AKA Sicily) Syria (Antioch, Damascus, Sidon), North italy (Arretium, Ariminum, Segesta, patavium) south greece (Thermon, Corinth, Sparta), the nile (Alexandria, Memphis, Thebes), and to some extent Britain (Londinium, Erebricum, the one is wales).


Brutii
Juno -This is what I use as the Brutii general temple. Reason being it's health bonus increases population growth.

Mercury -I limit this to cities that can have a huge trade income. They are Athens, Larrisa, Rhodes, Kydonia, Thessalonica, and Salona.

Mars -Much like Vulcan I limit this temple to the good troop producing areas. But unlike Vulcan with Mars you have to think long and hard before putting a governor in a city with this temple.