Hey. I'm flying tomorrow with them from Lanza to GC.
Deal as far as the info I have is as follows.
Hand luggage = 6kg
Check luggage = 20kg (unless you have Binter Mas/Binter Gold/Binter Silver - in which case 30kg)
But, if you are bringing sports equipment they give you an extra 5kg on top of stated checked in luggage. This is free, but their terms also state it is subject to availability of space in the hold.
I was told by their call centre to call per-flight to reserve a space for the surfboard and to let them know I was bringing one. The number to call is (0034) 902 391 392
There is a weird line on the end saying:
"Taking into account their properties, which normally prevent their transport on luggage belts, the use of a system that facilitates the carrying of this equipment from the check in area to the aircraft is left to the judgement of the company's staff. The passenger will be responsible for the costs arising from this item"
Which seems a bit vague. So, best smiles it is then, coupled with poor Spanish and puppy dog eyes.
Good luck. Hope that helps. The info is on the website I seem to recall.