*Totally* dependent on how you want them to sit in the mix. And *totally* dependent on a fairly stellar room.
That said - If you want very "up front" (rare, but it happens once in blue moon), close-up dynamics, top for the tap, bottom for the body. Tambourine from several feet away on-axis.
For "typical" I'd go with a stereo pair of SDC's or LDC's from around 5' away on the djembe, around 12-15' away for the tambourine.
That said - As it's a combo, try 7-10' away and see if that works well for both. *IN A DECENT ROOM* it should be fine. In a bad or poorly treated space, it's going to sound like complete crap from the get go, so go with the closer dynamic technique -- It doesn't sound great, but it'll have less of the space in it.
Either way, it's a lot of moving and experimentation to find the sweet spot in the room and the right sound of the instruments.