IMO it depends on the style of bed I have many times done low platform beds in spaces with a much higher ceiling IMO no real rule about head board height in propotion to ceiling height.. I think a rattan headbord would be very light looking in a large space but I would need to see your space and the bed you are thinking of. I think if you want a larger headbord maybe a platform bed is not the answer.

You could add other decor items above the headboard to balance out the space. Or try to find a rattan that has posts or a canopy.

A nine foot ceiling has become "standard" in new build. Hang art above the headboard. If you are dying for rattan, that's one thing..........but a four poster, and many many other beds can and will look fine.

46 with art above. It's really NOT an issue.

I might as well ask what size the rest of bedroom furniture is?

In a 15 by 15 room it really depends on whether you want the bed to dominate the room..

And where the doors and windows are...

Thanks everyone. I am not committed to a taller headboard, but am used to choosing furniture with some heft for this 1870s Victorian house. I am transitioning to a lighter casual style upstairs but still have many walnut period pieces to mix in.

So pretty Jan

As mentioned you can always place something above the bed to capture some of that space, and with the room being only 15x15 that might be the best solution in that the bed will not overwhelm the scale of the room.

If you consider woven banana leaf instead of simply rattan there are more choices, but the design is not as simple. Your other option is just to purchase a headboard and attach it to a frame of your choice. You typically will have options on the height.

I've had this Lane Furnishings bed for 15 years now and I would never get a bed with a footboard again. It is a pain to make the bed. A struggle

A LOW footboard is NO struggle. The last thing you want to contend with is a dust ruffle. Anyone can manage a low foot board. It puts the mattress above ...easy peasy. You still have a no hassle finished look to the bed.