@ retro V: The Bulbpaths have changed seriously since 0.23.
So bulbing religions is much easier now and you can bulb all of them if i remember right. (Don't know what happens when you research Philosophy before but i rather not do this before getting one of the early religions if i want any of them...)
So bulbing a religion + building a shrine (opening further specialist slots.) might be the better option for 2 GP.
Some Economic techs are indeed interesting to bulb. But thats more techs were the greath person just contributes most part of the research on higher difficulties. (+ getting a rather late tech early not only yields that tech but also other techs you can trade it for. So a one time vs. full yield calculation is not all that fair...

)
Also thats very much down to which type of greath people i have at hand. Engineers rather go into wonders nearly anytime, Sages into Academies, Prophets usually go for shrines (some of the later ones like Nox-Nocturnis offer serious stuff.) or Altar of the Luonnotar (which is really powerful in any sense from Altar 3 upwards.).
Bards and Merchants i do use to bulb with at times though. Some of the picks for them are rather nice in midgame as well. (As are their possibilities for Shrines.)
The only greath people i settle regularly if Nonsidar are merchants since that greath specialists do rock most of them all if limited (with sidar the choices are much less limited so i settle much more balanced with shades.).
Of course bulbing Drama, Arcane Lore and Military Strategy(?) excluded due to the free GP and slingshot possible by it (as well as the excellent opportunities to trade those techs since they are not all that powerful beyond that free greath person most of the time). So thats worth it most of the time.
Holy cities can be conquered just as well if you have a respecitve AI near in question.
Just be fast so not all to much of the religious Units start to appear. I find founding a religion in question is highly overrated. That one desciple doesn't make such a big difference imo and the shrine goes to the owner of the holy city in question not the founder of the religion. So don't waste your time in an unessesary race and don't frown if you lose such a race by a few turns.
But the best chance for bulbing an early religion super fast is beeing evil and getting Ceridwens event + picking a greath Prophet (requires quite some luck and can't be helped by anything else, but is not all that uncommon. Especially with living World.).
Thats the superhighway to the early religion of your choice. Just be sure to have enough gold handy to pay her out.

In such a case it might indeed pay off to aim for writing and get a greath sage for an academy. Since you can shot for the early religion anyways. An early academy just does so much for science.
OO can be gained rather easiely without bulbing even in higher difficulties unless the Lanun are in and have a very good start.
Also bulbing Priesthood can indeed be one of the most interesting fastbulbs (since it yields military power, sometimes support and economic advantage by fast-spreading temples. Early Cultists or Priests of Leaves are amazing and can tip a game or at least a few early-midgame wars indeed. Even moreso than the priests of later religions in question.)