I simply could not find relevant information regarding this question but can a character possessing both these ability charge great cleave and full attack all at the same time?
I don't think it will work.
Bull rush is normally a standard action. It can be used to replace the attack made at the end of the charge, but I think if you make the bull rush that you wont get to make the full attack.
The rules aren't particularly clear about this, but as a GM I would rule that it replaces all of the attacks you would otherwise get.
Yeah, that Bull Rush specifies "the" melee attack, to me implies that it's meant to replace the attacking portion of the charge completely. Being that a pounce isn't a singular attack to begin with, the wording kind of breaks down otherwise.
I think there's other weirdness with trying to do them all too, like you pounce, bull rush in place of your first attack, great cleave off your bull rush, go into your cleave string, finish that, then you're left with your remaining attacks, but the target of your pounce has been moved away. Does that mean you can change the target of your initial charge if there's still adjacent enemies? Charge requires you to move to the closest space from which you can attack your opponent, so the other targets should be invalid, especially if the opponent you bull rushed was initially in the way. Edit: Okay, I forgot that you can move WITH the target of your bullrush, but that causes more conflict, since you've now moved through blocked squares on your charge.
I would probably consider it as bull rush and pounce being two separate things that can replace "the" melee attack at the end of a charge.
So, lets see.
Bull rush states
You can make a bull rush as a standard action or as part of a charge, in place of the melee attack.
Charge states
Charging is a special full-round action that allows you to move up to twice your speed and attack during the action. (...) After moving, you may make a single melee attack. You get a +2 bonus on the attack roll and take a –2 penalty to your AC until the start of your next turn.
And then pounce
When a creature with this special attack makes a charge, it can make a full attack (including rake attacks if the creature also has the rake ability).
Since we know from an FAQ (which I can't find atm) that when it comes to iterative attacks only the 1st attack benefits from charging that would be the attack that can be converted into a bull rush. If you have pounce you would get the rest of your attacks as normal, but you couldn't use them to bull rush.
You should still be moving down your iteratives, since there's nothing in charge to suggest that the charge attack is special, as with AoOs and dual wielding, which makes this the only situation that could really matter in, in which case I'd still say that if it absolutely needs to be debated, once the bull rush is happening, either you lose your valid charge target, or you're no longer in a legal charge because of the movement you make. Not to mention interrupting the charge to do a cleave.