The 28-year-old, widely regarded as one of the best wingers in the Championship, netted five goals for the Baggies last season.
But he already has four this season after forming a devastating partnership with Matheus Pereira and Grady Diangana.
And Bilic says those goals have come from Phillips spending more time in the box – something the head coach believes he didn’t do enough last season.
“He (Phillips) was always a top player,” Bilic said.
“He always had that in him, but wingers have to be in and around the box.
“He likes to be around the box, but I said to him sometimes he wasn’t in the box enough.
“We’ve seen this season that, most of the time, when the ball comes in from the other side, he’s inside the box.
“That’s where the goals have been scored from.
“If you’re not in the box it’s very rare (to score as a winger).
“You can score a cracker from 25 yards or the one he scored against Nottingham Forest.
“But normally if you’re not in the box you’re going to score two goals a season, from penalties or whatever.
“If you’re in the box with his pace, physicality and skill, he’s going to get chances and then it’s all about how to convert them.
“At the moment he’s doing it well, long may it continue.”
A versatile player, Phillips has filled in at wing-back and in central midfield for Albion over the years.
But while he’s impressed with his finishing ability, Bilic doesn’t seem him playing as a centre-forward or as a false nine.
“I don’t like false nines – I like nines,” Bilic continued.
“Then with a nine, you can have another false nine. That makes him a false!
“Those false nines are very modern in football. Not so much now but a few years ago – it was like ‘who wants to play with nine? It’s better to play with false nine’.
“I never liked it to be fair. I prefer nines.”