does rebuttal trigger ravenbloom student twice when stealing a spell

Yes — twice, if you pay the [A] and actually steal the spell. Rebuttal itself counts as a spell you played (one Ravenbloom Student trigger when it resolves), and the stolen spell resolves under your control, which makes you the player who played it (one more trigger when it resolves).

This matches the established Mystic Reversal rulings (FAQ #4219, #5287): a spell whose control is taken off the chain is considered played by the new controller at resolution, so "When you play a spell" triggers fire for the stealer — not the original caster.

If you decline to pay the [A], Rebuttal just counters the spell instead, and a countered spell is never considered played (CR 426.1.b) — so only Rebuttal's own trigger fires, for +1 once.