I don't think Sbi would give Vistara card as LTF because it provides flight tickets as renewal benefit so you will charged every year until it brings some Fee waiver offer.
I would suggest not going for Vistara right now as Airline is sooner going to merge with Air India so it's not sure what will happen to this card.
Even if you manage to get LTF card it will get closed once Vistara merger takes place.