I don't think this is the counterexample that you intend. The prohibition is where this bribery is illegal in the foreign countries, even if it happens to be commonplace. Bribery is never "policy", else it would be called something else (as in the U.S., where we call it "campaign contributions").

It applies even when bribery is legal and does not distinguish whether bribery is legal or illegal.

After reading the linked Wikipedia page, if it's accurate then you seem to be correct. The act prohibits influencing foreign officials by giving them things of value, and doesn't mention whether that would be illegal in the foreign country. So it would seem that a U.S. corporation would be in violation of this law for doing in a foreign land what they routinely do within the U.S. (essentially all large U.S. businesses make, or aggregate, "campaign contributions" with the intent to influence lawmakers and other elected officials).

A very good point about the hypocrisy of the American system. Campaign contributions do look very much like bribery.