Yes rattan is a usable material. Bows can be made a lot shorter then with wood, because it's bendy. And they should be made a lot wider towards the tips, because it's bendy. You can make a bow for 0,8m draw with as little as 1,5m ttt-length (including a stiff handle section and some static recurves. Bending can be done with a heat gun in no time, and you can do such horrible stuff as tillering with a spokeshave on the back of the bow ....
The disadvantages are glueing on handles is tricky, because it's so fibrous. If things go wrong, you only glue on the handle to one layer of fibres, and then they just split of ... so adding any kind of safety-wraping will be a good idea. It's hard to get the surface pretty ... and wooden bows often have better cast.
Still ... I find it is a joy to work it.
