do you mean to place another 3k3 to PWON and Gnd?
Yes

if I use 3.3v to PIC16F628A will communicate well to the GSM module?
Yes

I tried to supply the mcu with 3.3v with blinking program on PortB.0 but using the voltage meter no deflection shown.
Did you disable brown-out reset feature?

Naturally if you use 3.3V you don't need the devider!


Cheers

Al.