Short answer, yes.
Way back in the day there was a monk module where any character could learn a selection of monk abilities from "mad monkey" in preparation for the final conflict.
Dragon magazine put out tons of feats that could be purchased for xp.
A few modules hosted on the wizards site grant bonus feats.
Mythic tiers are basically powerful bonus feats.
It might even be fair to let players use downtime retraining rules to purchase extra feats. This would address feat tax, the "too much wealth" problem (not really a problem, but that's a different discussion) and fill the space between adventures while encouraging players to develop contacts.
|Mark Hoover 330|
Weirdly I was just having a similar discussion with a player in my homebrew game. The difference though was that we were debating adding a list of minor, non-combat or low-impact Feats that players could choose from instead of specific bonus feats for plot-related rewards.
I guess he'd implemented this houserule in his own games many years ago. The list would include stuff like non-combat Feats such as skill focus feats, extra traits, or even things as powerful as boon companion. He also suggested "low impact" feats like Arc Slinger or Undersize Mount.
The point of these bonus Feats would be to reward his players for good play, hitting key milestones in the plot, or creative problem solving. My player however suggested there be some kind of justification or rationale for the feat obtained. For example if the PC wizard chose Skill Focus: Use Magic Device but she'd never even picked up a wand in game to that point, my player (as GM in his own game) would require some Downtime during which the wizard PC was meddling with magic devices, researching magical theory, etc.
Hell's Rebels (in the player's guide) and Ironfang Invasion (Via Lands of Conflict) both have a subsystem that awards bonus feats for progress. These are locked to feats that aren't very useful most of the time (+2/+2, though Hell's Rebels is the campaign that would benefit from Conceal Spell so Deceitful isn't a terrible pick)
3.5 had locations that granted feats. Most of these are remembered because they had GP costs for calculating how much a feat was worth since it expected this reward would be instead of treasure. There's lists of them somewhere because it effectively meant you could buy some feats.
I recall 3.X allowed a feat as a magic item for an average of 10,000 gp + 5,000 gp for each prereq it drops.
PF does have a few feats as magic items and thus purchasable for gp.
I recall running one module in 3.X gave feats if your character got hit by the bad guys' cyborg making machine. [It programmed the feats into you.]
I also went through the "mad monkey" module mentioned above. I recall the monkey in question was the Chinese god "Monkey".