Your lineage is important. Not is so much as to what it is, but more in the fact that you can trace the line back to Mikao Usui. This shows that you have been attuned by a genuine Reiki master/teacher. There are people purporting to teach Reiki who have themselves never been attuned and cannot, therefore, pass Reiki onto anyone else. The existence of a lineage will demonstrate this is not the case. The lineage below shows the Reiki master/teachers who have passed the energy from Mikao Usui to me.
Taggart King - https://www.reiki-evolution.co.uk
Frans Stiene - http://www.ihreiki.com
Tadao Yamaguchi - http://www.jikidenreiki.co.uk
Rev. Leah Brenda Smith - http://leahbrendasmith.com
William Lee Rand - http://www.reiki.org
Richard Jones - http://www.thedawn.co.uk
Rachael Crawford - http://psychicworldofrachaelcrawford.co.uk