No.
From GameFaqs (so from before TSLRCM was even available);
Q - What are the perks for getting Light Side, or Dark Side Mastery?
A - Mastery occurs when you are PERFECTLY in the Light or Dark. You get a
bonus:
Jedi Sentinel/Watchmen > +3 CON
Jedi Guardian/Jedi Weapon Master > +3 STR
Jedi Consular/Jedi Master > +3 WIS
Sith Marauder > +1 to 8 extra damage
Sith Assassin > +3 DEX
Sith Lord > +50 Force Points
Note: If you get perfect dark side mastery while still in one of the
original 3 classes, you will get the Sith bonus. That is, a
Guardian will get +1 to 8 extra damage, a Sentinel will get
+3 DEX and a Consular will get +50 FP. [from Sam Lay]
Bonuses from original classes stick around after you get your prestige
class. So, a Guardian > Weapon Master has a +6 STR bonus. It won't SHOW
that you get a +6, you still see "+3 STR", but you get the full +6. You
can test this by stripping your character of all items and looking at
your Character screen. Your stats with the bonuses will highlight in
yellow, and then you can compare those numbers with the numbers you see
at level up (which are your "real" numbers).