weapon proficiency

[balderdash]

if my class make me proficiant with all martial weapons do i still need weapon proficiancy for a single weapon or is implied i have the feat for all martial weapons

[Mage Evolving]

As long as the weapon isn't exotic you can use it.

[KaeYoss]

Proficient in all martial weapons means you basically get the Martial Weapon Proficiency Feat for each martial weapon.

And these classes basically always get proficiency in all simple weapons, too, so that's even more feats they basically have.

[Starglim]

Yes, you effectively have MWP for every martial weapon, as well as for attacks that count as martial weapons, such as using a bastard sword two-handed or a sawtooth sabre as a one-handed weapon. This counts for prerequisites of feats, prestige classes and so on, as well as in combat.

This doesn't apply to simple weapons, although, as KaeYoss mentioned, almost every ability that grants you proficiency with all martial weapons also gives you all simple weapons.