Dragon Style says this:
Prerequisites: Str 15, Improved Unarmed Strike, Acrobatics 3 ranks.
Benefit: While using this style, you gain a +2 bonus on saving throws against sleep effects, paralysis effects, and stunning effects. You ignore difficult terrain when you charge, run, or withdraw. You can also charge through squares that contain allies. Further, you can add 1-1/2 times your Strength bonus on the damage roll for your first unarmed strike on a given round.
And thus only applies to the first iterative.
Dragon Ferocity says this:
Benefit: While using Dragon Style, you gain a bonus on unarmed strike damage rolls equal to half your Strength bonus. When you score a critical hit or a successful Stunning Fist attempt against an opponent while using this style, that opponent is also shaken for a number of rounds equal to 1d4 + your Strength bonus.
And thus applies to all unarmed attacks.
Horn of the Criosphinx says this:
Prerequisite(s): Base attack bonus +6 or monk level 6th.
Benefit(s): Whenever you make a successful charge attack while wielding a two-handed weapon in both hands, add two times your Strength bonus to the damage roll.
Normal: A character wielding a two-handed weapon adds 1-1/2 times her Strength bonus to damage rolls.
Special: A monk can use this feat as long as he is wielding a two-handed weapon or both his hands are empty.
Note: A monk can take any of these feats as bonus feats at the indicated levels. To benefit from the feats, monks must have both hands free and capable of delivering an unarmed strike.
And doesn't specify that it only applies to the first attack. Where would you get that idea? If a monk got pounce from some other source (say, wildshape), he would get this benefit on all his unarmed strikes, would he not? Even sans pummeling style and just normal iteratives?