Like when building the encounter total experience, treasures also should figure out the total between all creatures on the encounter based on the encounter difficulty. Depending on the difference between the encounter level and the party average level, you should consider the encounter difficulty (easy, average, hard, challenging and epic) as well, which can adjust how much treasure the encounter should have.
Table: Treasure Values per Encounter lists the amount of treasure each encounter should award based on the average level of the PCs and the speed of the campaign’s XP progression (slow, medium, or fast). Easy encounters should award treasure one level lower than the PCs’ average level. Challenging, hard, and epic encounters should award treasure one, two, or three levels higher than the PCs’ average level, respectively. If you are running a low-fantasy game, cut these values in half. If you are running a high-fantasy game, double these values.
Encounters against NPCs typically award three times the treasure a monster-based encounter awards, due to NPC gear. To compensate, make sure the PCs face off against a pair of additional encounters that award little in the way of treasure. Animals, plants, constructs, mindless undead, oozes, and traps are great “low treasure” encounters. Alternatively, if the PCs face a number of creatures with little or no treasure, they should have the opportunity to acquire a number of significantly more valuable objects sometime in the near future to make up for the imbalance. As a general rule, PCs should not own any magic item worth more than half their total character wealth, so make sure to check before awarding expensive magic items.
Say, for example, that this encounter is aimed at a party where all characters are 9th level, then the treasure should be average and use the treasure as a CR 9 encounter normally (4,250 gp). However, if this is a 10th level party, then even considering that this is a CR 9 encounter, you should award treasure as a CR 8 encounter (3,350 gp), since this encounter is too easy for the party to handle.
The Treasure field on the bestiary entry is a quick shortcut for when you are using a single creature on your encounter, so you have an idea of what kind of treasure to place on the encounter on a quick look at the creature. Also, to figure out how to balance out the treasure between multiple encounters, as some creatures will have no treasure, while others might have double or triple.
Keep in mind that this is merely the average, you can go under or above that value if you so wish. But the game expects the party to have a certain amount of wealth once they level up, even if that isn't necessary to be enforced. If you want your double chimera encounter to award 5,200 gp worth of treasure, that is fine (really) and the game will not break because of that. The characters could have some extra coins now, but you can compensate that when they travel through a forest encountering animals, or when they find several traps on the next dungeon.