Quote Originally Posted by vegetalss4 View Post
In addition to a (relatively small) bonus it also allows any dwarf that get within 10 ft to make a search check as through they were actively searching.
However given how few skill points clerics get, and the fact that search is a cross class skill for them, it's pretty likely that none of them invested enough into it to discover the compartment if it is well made.
That too, plus the fact that hidden secrets tend to be really well hidden; it might even be magically concealed.