No, it dones not apply to magic damage. You can check ktullanux card script: { bonus2 bAddEle,Ele_Fire,50; bonus5 bAutoSpellWhenHit,"WZ_FROSTNOVA",10,20,BF_WEAPON|BF_MAGIC,0; },{},{} Has exactly the same effect as Vandon: { bonus2 bAddEle,Ele_Fire,20; },{},{}
So, it only applies to physical and ranged attacks.