bonus bMaxHPrate,100; bMaxSPrate,100; will increase the max HP and SP
Try to look at https://github.com/rathena/rathena/blob/master/doc/item_bonus.txt#L152
You could use these bonuses depending of what you really want to achieve
bonus bHPrecovRate,n; Natural HP recovery ratio + n%
bonus bSPrecovRate,n; Natural SP recovery ratio + n%
bonus2 bHPRegenRate,n,t; Gain n HP every t milliseconds
bonus2 bSPRegenRate,n,t; Gain n SP every t milliseconds
bonus2 bRegenPercentHP,n,t; Gain n% of max HP every t milliseconds
bonus2 bRegenPercentSP,n,t; Gain n% of max SP every t milliseconds