Searle claims that social reality is ontologically subjective. By this, should one interpret him as meaning that our perception of reality is ontologically subjective since perception requires conscious mental states? For, he acknowledges unconscious mental states. And, one could argue that unconscious mental states do not possess the properties of being ontologically and epistemologically subjective. In that case, not all of social reality is ontologically subjective.
I think this is a very interesting question (and improved in tone after the edit).
There's some heavy terminology getting thrown about in your question, terminology with debatable meaning. So to start out, I'm going to give the definitions I work from (I've read some Searle but I'm a Hegel scholar -- not a social ontology scholar). I take "ontologically subjective" to mean that if you had a world with no subjects, such facts would not exist or if you have a world with different subjects, the same objective data might have a different meaning to those subjects.I take perception to be the recognition of something inside or outside of the self as a type of object. I take "unconscious mental state" to be a state occurring in a mind about which that mind is not aware.
Given these definitions, I do not find the critique against Searle damning to his position. I take the force of the critique as you've articulated to be.
(1) Social objects are ontologically subjective (2) Searle sees perception as ontologically subjective (3) Subjects can have states they do not perceive ... Therefore (C1) Therefore subjects can have states that are not ontologically subjective Thus, (C2) not all of social reality is ontologically subjective
I think there are two errors or at least ellipses that need to be solved to make the critique forceful. First, before (C1), it does not specifically matter that a subject experiences mental states that that subject does not perceive and which are part of the social ontology.
Or to restate it, I don't think Searle commits himself to a universal perception thesis regarding ontologically subjective social reality. It is possible for one or more subjects not to perceive such a state without eviscerating the existence of the state.
The second gap seems to me to be between (C1) and (C2). There the problem appears to me that Searle is protected through his definition of social reality. If social is by definition something ontologically subjective, then the discovery of some mental state merely would indicate that state is not part of the social reality. To give this second conclusion force, you would need to prove that social reality is an empty category. And all states lie outside of it.
I don't take (at least on my brief reading) the interpretation that Searle believes all of our reality is social reality, so proving one thing is not social reality is not enough. You either need to prove something that appears as the quintessential case of social reality is no ontologically subjective or that there are no such cases where something is social reality or that they are so rare that we should ignore them.