the argument "SMOKER WAS THERE" hence government didn't bother giving Sanji a bounty even tho they knew.. is honestly baseless and nonsensical argument given the context.. the HQ literally capped smoker and he couldn't refute their false entitlement. So saying Smoker knew.. doesn't prove shit since the HQ doesn't give a crap about what smokey says .. and knowing smokey's personality he's a guy who's at odds with the government and thinks subjectively.
Smoker just knew that he was saved by Sanji while gawking at his entry, so assuming that he knew everything.. is just a false and unsubstantiated headcanon.. he didn't know crap about what happened in Little garden nor did he know what sanji was scheming . he wasn't there when sanji bet mr 2..coz mr 2 got caught by Rear Admiral Hina.
even and idiot could compare what sanji pulled off to zoro and luffy and conclude that he did way more significant and decisive acts in the grand scheme of things.. him not getting a bounty is evidence that what sanji did was too discreet.. even for someone who just merely got saved like smokey doesn't know crap. except sanji bet a flipin croc and helped him out and in exchange he let them get away.
you can literally count em on your fingers the deeds sanji did and how substantial they were in the stretch since Little garden..
after considering his deeds coming to the conclusion that he didn't do enough for a bounty... is just admitting that you need to book an appointment for therapy.. and state your problem as "unable to gauge and quantify worth of things, and reaching bias conclusion" I'm sure they'll be prone to help such a sensitive case.