Good Bluff?

[NYTyler]

PokerStars No-Limit Hold'em Tourney, Big Blind is t1000 (9 handed) Poker Stars Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

SB (t28519)
Hero (t26958)
UTG (t48961)
UTG+1 (t8670)
MP1 (t20859)
MP2 (t13706)
MP3 (t18668)
CO (t45714)
Button (t57945)

Preflop: Hero is BB with A[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/heart.gif[/img].
<font color="#666666">3 folds</font>, MP2 calls t1000, <font color="#666666">3 folds</font>, SB completes, <font color="#CC3333">Hero raises to t4500</font>, MP2 folds, SB calls t3500.

Flop: (t10300) 5[img]/images/graemlins/diamond.gif[/img], J[img]/images/graemlins/club.gif[/img], 3[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">SB bets t7000</font>, Hero calls t7000.

Turn: (t24300) J[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
SB checks, <font color="#CC3333">Hero bets t15358 (All-In)</font>, SB folds.

Final Pot: t8942

Villain has been raising his SB constantly when nobody else plays and betting out first at a lot of hands when the pot is heads up or sometimes three-ways. He has done so and most of the time rarely had to show down his hand when he did this. Is this an ok bluff?