First of all, prepare to buy 5-7 hours of your time depending on the bus that you want to take.
Bacolod - Iloilo - Boracay: From Bacolod port, take the fast craft; it would take an hour and a half to go to Iloilo. I would suggest that you take the first trip. There are 3 shipping lines that you may want to choose, these are SuperCat, Weesam and Ocean Jet. These 3 fast crafts have promos (most of the time) and for me, I would take Weesam or SuperCat. Go first class if you want Weesam and prepare for about 500php for a round-trip ticket. They usually offer promos for round-trips and same goes with SuperCat. Take the first trip, for Weesam, they depart at 06:30 am and 06:00 am for SuperCat if you want an earlier trip.