This particular Android 6.0 Marshmallow update will see Sprint’s LG G4 owners gain access to the standard slew of Android 6.0 features, where among them would include Doze. Doze carries the promise of improving the overall battery life, complete with lower standby power use; while Google Now on Tap will allow one to obtain additional information concerning whatever you are interested in right there and then on the display itself, in addition to redesigned app permissions.
History has shown that Sprint’s updates tend to roll out across a variety of stages, hence you might actually have to play the patience card with this as well before you start to see a download request for the Android 6.0 Marshmallow update appear on your handset. In the meantime, if the impatience bug bites you, you can always opt to perform a manual check on your device. [Sprint Support Page]