Most special bldg's can NOT be plundered. According to the Official FOE wiki.
I wouldn't say that. Plenty can. Anything in a set can be plundered- Cherry Blossom, Palace, Winter, etc... Any special production building- Terrace Farm, Bazaar, Cider Mill, Masquerade Ball, Soccer Field, etc... It is pretty split, honestly.
As Agent said, if it can be motivated, it can't be plundered when motivated. (It can be plundered when unmotivated, but the likelihood is low since the motivation triggers the special feature with special buildings.) If a building can't be motivated, it can always be plundered.