Michu, who joined Swansea for just £2m back in 2012, scored 22 goals in all competitions last season, while Bony has already scored six having joined the club in the summer.
"They have [made an impact]. Especially when Michu [came] in for the money Swansea paid for him. What he's done for the club has been unbelievable," said Trundle when asked about the strikers' partnership by ITV4.
"He's a class striker. He's not only one who scores goals, but we'll see him chasing back into his own half by the box, he's got a great work rate. With Bony, he's more of an out and out striker where he'll be the last man and likes to back into defenders, get his body in and get his shots off."
Swansea currently sit 13th in the Premier League, having won two, drawn one and lost three of their opening fixtures this season.