Agree on the cuttings, but I would not recommend keeping any foreign substances like elastic bands and lead ties in an aquarium with fish. Lead is a heavy metal and highly toxic to fish and plants; while the amount of lead from one plant tie might be minimal, it may stay in the aquarium and build up over time, or with more ties obviously there is more lead, and it will leech into the water. Elastic bands may degenerate in time, but I would here be more afraid of fish chewing them.
These things should always be removed before planting in an aquarium. The stems can be pushed down into the substrate as far as needed to hold them (should fish be dislodging them). I would separate Wisteria
stems a bit anyway, because bundled together the lower leaves will definitely die off. Keeping them apart, perhaps in groups of two or three, is less likely to cause this. If you look at the photos of my 70g SE Asian aquarium you'll see Wisteria
all around the tank in individual stems, and it is quite effective; I have also allowed it to grow along the surface, it provides excellent cover for fry (pygmy Sparkling Gourami
and Chocolate Gourami
in this tank) and good browsing areas for the gourami.