In the new solo adveture when you buff a card from bob, your not actually buffing the card but instead changing its base stats, for example if a 1 cost card was buffed but had its mana raised or lowered it would no longer count as a 1 cost card for quests and minion and if returned to your hand it would keep any extra health, attack or discounts added via bob.
Bonus fact the “Super simian sphere” is that it spawns a mukla and then adds buffs, if mukla gets returned to your hand with for example vanish, it just becomes a normal king mukla