This is how you get the set of files to check:
files whose(name of it starts with "com.apple.Bluetooth." AND name of it as lowercase ends with ".plist") of folders "Library/Preferences/ByHost" of folders of folders "/Users"
I don’t have an XML representation of these files handy to write the relevance against.
You might be better off controlling this setting using a profile, or MCX to profile, or Local MCX. This is particularly true if you want to set this setting to a particular value and NOT let users change it ever again.
You can set a profile with a command through BigFix, but it is hard to tell if that profile is in place or not, so you might want to tag the system as having the profile so that can be used in relevance.
You should be able to use Local MCX using BigFix, but it might not be worthwhile to pursue since MCX seems a bit old school at this point.