Personally speaking from experience, the Filter on the bump I set to 0. In my own findings it basically gives you a bit more of a sharper look to the bump without havingto resort to high values in the bump setting itself. As for that particular setting, I usually start with a value of 0.010 for starting and obviously decrease or increase accordingly. But most of the time with things like clothing I'd probably go with the above setting.
Also try feeding the bump map into the color gain (of the bump map) as well as the bump node itself, watch the result, its pretty good too.
Also I find that alot of people go way too high with bump settings. Bump is only really becomes apparent at a certain distance, on different materials, so a bit of research on your materials is always worth a go. I dont mean yours in particular, Im just generalisingas an overall picture. However heavy materials like denim and leather may feel like they need a heavy bump to make them obvious but this isnt always the case. Materials such as hessian or sack cloth would blah blah.
Im ranting now.
Hope this helps in any way or form