Andreas, Yes, do a scarf joint(mated 45 degree edges) at glue up and add a thread wrap to secure it. On the recurve I used silk thread(red) to complete the termination at the limb tip and I think I used hemp cord for the same on "Herb's Bow". I set both wraps in superglue.
To apply the bark size both the bows back and bark first then add the glue to both at glue up. I used old bed sheets, torn in 2" strips to wrap the glued down bark. This allows good air circulation as it secures the bark backing. After about an hour(with TBIII) I removed the wrap, carefully cleaned up the excess glue and did an initial trimming of the bark along the edges of the limbs. Be careful not to pull the bark loose at this time. After 24 hours you should be able to smooth the the edges for a nice clean transition. A file or sandpaper should work well here.