Each time a wish is made, either by you or automatically after a wish is granted, it is based on how many LP tokens you hold at the time the wish is made. So if you made a wish and had 10 LP tokens and then one day later add another 5 LP tokens, when this wish is granted the rewards will be based on the 10 LP tokens you held at the time the wish was made. The subsequent wish will be based on 15 LP tokens.