I was wanting to play a Magus/wizard, and was wondering if spell combat would work with spells from both classes?
Only spells that are on the magus list that the character has memorised (from any class, so Wizard counts) can be used in spell combat. The quote is:
As a full-round action, he can make all of his attacks with his melee weapon at a –2 penalty and can also cast any spell from the magus spell list with a casting time of 1 standard action (any attack roll made as part of this spell also takes this penalty).
Now I'd normally interpret this as any "magus spells" but we're going for Rules as Written here, so...
The magus spell list includes a lot of wizard spells, as the magus gets their spells from the core wizard list anyway but some wizard spells will NOT be a magus spell, so they can't be used.
However there is one more major problem. A multiclass magus still incurs the normal arcane spell failure chance for arcane spells received from other classes.
So if the magus has any armour on when they try to cast their Wizard spells as spell combat, they'll get a spell failure chance, which isn't worth going for, believe me.
That all said; it's really not worth multiclassing wizard/magus - stick with just one!
Also as mentioned there is a Magus Arcana Broad Study which allows use of spells from another class in spellstrike. So despite the bad wording in the original text it does appear the intent is that only the spells memorised as a magus should be used, but above is strictly RAW.