Can black triangles from IPR be corrected with bonding?

Black Triangles form when the interproximal contact is too far from the the underlying bone.  During Invisalign treatment, when teeth are being shifted, both the bone and tissue is being remodeled.  It is best to finish treatment and wait for the teeth and tissue to settle. If you still have black triangles at the end of treatment then at that time the area needs to be evaluated.  

It's too early to say.  You may see improvement as the teeth align.  If you are still unhappy with the triangles once the teeth are aligned, discuss the options with your dentist.  If the space is present in many areas, I would recommend adding slightly more IPR and bringing the teeth closer together if possible.  This is a much cleaner way of eliminating the space.

wait till complete space closure + more 3 months gum tissue will grow and fill all that space. later u feel any space discuss with yr dentist.

It is hard to bond the stress of teeth you're discussing. Typically the gums will grow into the area, once the teeth are done moving.If you're concerned about further IPR, your provider can tell you if there is any more recommended on your plan.

Depends on lots of stuff so can't say one thing or the other is the solution.  Usually IPR is better up to a point because does not need replacing as bonding will.  Also depends a lot on the health of the gums.  When the teeth are straight, revisit the subject with your dentist.