Do you get any special bonus for doing it like in the previous games? I couldn't find anything on Clouds of Xeen.

Donating to temples gives you an assortment of spells the same as the Day of Protection clerical spell that lasts for the remainder of the day. The number of times you need to donate consecutively to get the blessing seems random, but it's less than 10 in most cases. Once your cleric gets the spell, temple blessings become obsolete, unless you want to save some spell points.

Hey,
I know what donating does. The number of times by the way is not random, but is dependent on the day of the week (day mod 10), and it also affects the power of the effects. Also, it's not exactly like day of protection: it doesn't give you protection from elements, but gives you power shield and clairvoyance amongst other things.

However in previous games, donating to all temples (i.e. temples in all cities) had an additional special effect or were needed for a quest. I found nothing like this in Clouds of Xeen, but I'm wondering if it is something I missed.

Yeah I don't think there is any special effect for donating at each town in World of Xeen.