Currently on P99 Cindas has no benefit from using a wind instrument and caps at a whopping +610 faction at level 60 -- based on its description on Allakhazam... which is unfortunately wrong.
Right now on live/test the formula for Cinda's is [(Level+1)x10] x Instrument Modifier and it caps out at +300. This post from 2002 detailing an AAs affect on different songs mentions this +300 cap and I have searched every mention of "bard" and "cinda" from 1999 through 2006/2007 and found nothing to suggest that it was ever nerfed to this cap.
https://web.archive.org/web/20020426...tt/jamfest.php
This would also make sense seeing as Enchanter's final faction spell Collaboration gives +300 faction.
This post is to give folks a chance to provide evidence that Cinda's used to give more faction than this but was later nerfed to its current state on live. I wanted to find proof of this (being a Bard and loving my faction) but unfortunately I could not.