It's been mentioned numerous times before, but generally Flying Blue availability for US domestic and TPAC flights is very limited to non-existent because it depends on what the partenaire decides to release to FB. Furthermore, as also mentioned, it's very difficult to obtain and retain status because all the flights within the US, even to Hawaii, earn you only domestic XP; thus 2 in Y and 6 in J; there is no first-class within the US.

It's recommended to use the Delta programme as a frequent flyer if you're based in the US.