There's no shame in looking up information on the internet (especially Bulba/Serebii) instead of relying on these "friends" have either got it wrong or lied to you purposefully (it's what a lot of us do).
I'm not sure what else needs to be said, but I'd like for this to get back on topic so,
I think the surfing music is more acceptable than the bike music. The surfing music usually fits more and sounds better. The surfing music is also less intrusive. When you hear the surfing music usually you're going to be on a dedicated surfing route with little land where the surfing music is thematically fitting, rather than the bike which you use on (almost) all land and land has a much greater variety of music than water.
Also: this music can be done right. The RSE Dive theme is a good example.