If you use the proper size bolts and have no gap between the fuse and wing, nylon bolts are far better than rubber bands, even for a trainer. On your particular plane, 6X32 Nylon would be more than adequate to retain the wing and; should the inevitable crash occur, the wing bolts will shear with no damage to either wing or fuse caused by the attachment. I use 10X32 on my bigger planes (1/4 scale) and they are more than adequate for up to 15 pound airobatic planes.