Not sure when that was changed then , when i looked all that time back it still said it required 28 ( which i can get to ) and i haven't seen anything indicating it was changed 
That , together with "chosen weapon " giving others the opportunity to take " overwhelming criticals " and with that opening up " devastating criticals " reduces a "weapon-master" to a simple fighter that is 3 points faster then a " normal " fighter at lvl 13 WM lvl's .
nice to hear the "weapon-master " has been reduced to just that , no wonder no-one takes more then 7 lvl's in it ( since you can afford to miss the last +1 on attacks if you can switch it for "epic damage reduction " ...a feat fighters get ...but weapon-masters don't )
Dear Jan
Getting epic lvls in WM is not a waste. At lvl 20 WM ( that you will soon be)you will have All the WM benefits, + 7 AB more then a regular fighter, and also you have gotten 3 bonus feats at lvl 13,16 and 19. This means your fighter have extremly high AB and can hit almost everything. Or he can stand in Improved expertise and have +10 AC and still have a good hit ratio due to his high AB
As others have stated. No matter what the bonus feats are in Lore for the specificik class. If you don't have the prerequisite for it you won't be able to choose them.
So if you don't planning to multiclass Barion more and take a third class I would say keep on trucking whith WM lvls... He will be the meanest Bloody swordsman on Layo.. In epic battles when fighting the big Boss or dragons the rest will be hitting air while Barion is bringing it down on it knees whith his Criticals hits..
*cheers*
