I made up a counter top of teak strips glued to marine ply. using epoxy resin -- I am sure lots of people will say its wrong, but has lasted a year now with no ill effects. I wiped the wood down with meths to get rid of the oil btw.
Agree with using West Epoxy. Howells recommended this method to me when I bought teak strips to repair my cockpit gratings recently. It works brilliantly, though of course, only time will tell in the long run!! You don't need a primer, just paint the epoxy onto BOTH clean surfaces, then clamp up just tight enough to hold in place. Clamping too tightly will just squeeze all that expensive epoxy out and ruin your day!!
I have a lot of teak (Fisher 30) on my boat which needs repairs. I have used Araldit (2 part epoxy) many times and had good results. The repaired joints have survived several years without breaking. Tip: do not squezze to much of the glue out of the joint.
PVA works just as well as epoxy and is cheaper not to mention easier to clean up afterwards.
More important is cleaning / deoiling the teak before applying any adhesive. Yes meths works up to a point but acetone would be my choice based on many years working with teak and other oily woods.
If you decide to use west system do ensure you add some microfibers to the mixed resin/hardner or failing that at least add some collodial silica (a poor second option compared with adding microfibres)