The 2016 Pilot uses 8 x18 ET55 Offset Rim ; 245/60/18 tire
It also uses the 8 x20 ET55 Rim. 245/50/20 tire (on the Pilot Elite).
The bolt pattern is 5 x 120 for both.
I must say that the 55mm offset for the Pilot Rim seems a bit high. Check the rim, it should be stamped on the inside.
The 2008 Ridgline uses a 7.5 x 17 ET45 Rim, with a bolt patter of 5 x 120 with a 245/65/17 tire.
So to answer the question: will it fit?
as far as Bolt Pattern is concerned, YES that will fit.
as far as 18" and 20 " Tire size is concerned (assuming you are using the OEM pilot sizes).. YES, however, Tire is 10 mm closer to suspension/brakes components. Rim is 16 mm closer to suspension/brakes components. Make sure that you have enough room for that.
Aesthetically speaking the wheel will be further under the fender by 10mm (assuming the offset is indeed 55mm for the Pilot rim). When it comes time to replace the tires you could try 265/55/18 and that Aesthetically speaking will look the same.