How to build tightness in the band

this all boils down to individual skill and practising as a band.

how long have you been playing bass and playing with your drummer?
Been playing covers most of the time so as individuals we do our homework but now i embarking into originals.

Its quite a headache figuring out whether Bass should follow the drummer or drummer to follow the bass?

As a bassist, i would usually try to coordinate myself with the drummer kick drum, is that correct?
by right, whole of band should follow drummer.

but sometimes the drummer not zai.... then... heh.
It's all in the feel and how you connect more with your band member

Actually it's not just bass and the drums to coordinate together but more of the whole band as a whole.

If everybody follows each other with the groove ... doesn't matter whether it's just a casual jamming, doing an original or a cover ... your band will always be tight.

listening to each other and know what the others are playing is important to make your band tight.

As a bassist, i just play some groove and trust my drummer to groove the same ... or it works backwards ... doesnt matter

Just groove it

How do you achieve that? Jam more and practise more with your band members.
practice with your bandmates as often as possible, practice in complete darkness with your band so all of you can play blind, and adapt to changes on the fly (e.g. if your singer starts singing a phrase earlier than he's supposed to, everyone needs to adapt accordingly)

for my band, whatever happens, we'll follow the drummer. so, basicly, if the drummer go way too fast, one of us will have to tell to tell him or worst come to worstl, we'll have to follow him. one thing is practice together often.

any other methods to share?
hmmm, go on outings together that are not music related, e.g. eat lunch, go watch movies, go swimming, get to know your bandmates better, den u noe how they tick, den can i meant manage each other better
Improv a 15 minute piece everytime you start the jam. Let each person in the band dictate the changes through their playing.