Does a "natural / cream" color Barong look good on a groom when the bride is wearing a pure white dress?

Absolutely! Especially when a white, long sleeve undershirt is worn with the Barong, the Barong looks nearly white. See photos on the "Filipino Wedding" web page (link to Filipino Wedding page).

If you wish to wear a White Jusi Barong, check out (link to White Jusi Fabric Barongs page).