Good one! It's really hard to pray for those who choose to be deluded and guided by other spirits, isn't it? It's hard for me anyway.
I believe that this is provided for in the 1979 BCP. We often use Form III of the Prayers of the People, one part of which goes like this (I added V: and R:);
V: We pray for all bishops, priests, and deacons;
R: That they may be faithful ministers of your Word and Sacraments.
Sounds pretty appropriate to me.
You could pray for someone like Spong, but I think his beliefs are self-inflicted.
He is a bold blasphemer with no wish for repentence.