Mounting 2'x3' Glass whiteboard, drywall over concrete
I'd drill into the concrete and use some sort of masonry anchors, wall plugs should be sufficient for the white board because it goes close to the wall.

For a bicycle something stronger is needed, because it's heavier and mounts further form the wall. I'd go with expanding bolts. 10mm seems a good size.

Or just drill into the wall an glue  steel bars in with a 2-part resin. (Chemset, builders filler etc), then put somethign over the bars to make them look nice.