NARA should not have been confused about the regiment, since there is "U.S." in the name (indicating Regular Army). Sometimes files get lost or misfiled, and you get a rejection slip instead of a file, even when you go there in person.
The image that you posted was the file jacket of an 1812 pension file. Because the bounty land warrant number was written on the file jacket, there would not be a separate bounty land application file, the bounty land application paperwork would all be included with the pension file. You can go to the BLM website at: www.glorecords.blm.gov
and click on "land patents", change the state to "any state" (using the pull-down list), and then uncheck the little box underneath that says, "search patentees". Leave the one checked that says, "search warrantees". Since you know he was a soldier who got a bounty land warrant, he would be the "warrantee". Then search his name and he should come up with a little "w" beside his name. If he was the one who used the warrant to get land, he will also be listed with a "p" for patentee. If he sold his warrant certificate to someone else, that person will be listed with a "p".
The transaction for the sale of the warrant will be listed on the reverse side of the warrant certificate itself. This certificate is filed separately and not part of the pension and/or bounty land application files.
As far as "where his bounty was"...if he sold the warrant certificate to someone else, then he never got land. If he was interested in patenting land himself, he would have been able to choose land in any of the public land states. The BLM website lists all of the original patentees who purchased land directly from the federal government, whether with a military warrant or some other way.
Another little tidbit when working with bounty land warrants--in the number "3290-160-50", the 3290 is the warrant number (listed as the "document number" on the BLM website), the 160 is the number of acres that the warrant was good for, and 50 is the last two digits of the year that the act was passed that this person was applying for land under. Congress passed many different acts over the years for bounty land, getting more generous as time went on. The acts were retroactive, so any veteran of any war (including the Revolution) who got 40 or 60 or 80 acres of land under a previous act, could come back and apply for more under later acts. That is why many soldiers have two bounty land warrants. This particular soldier only has one warrant, because it is for 160 acres, and that was the maximum amount. The last bounty land act was passed in 1855. There was no bounty land for Civil War and later.