Bohr effect in respiration
Would I be correct in saying that the Bohr effect is ONLY related to the concentration of [H+] in the tissues.


I would say no. Because oxygen binding affinity is inversely related to both [1]:


high $[H^+]$ concentration and
$CO_2$ increase (which is can be a consequence of the first)


$CO_2$ is involved in the Bohr effect:


  The biological significance of the negative influence of the carbon dioxide pressure on the oxygen binding of blood is obviously very big. [...] During the bloods movement through the body the oxygen-pressure will decrease to a relatively low value, whereas at the same time the carbon dioxide-pressure rises. This will greatly support the oxygen release from the blood, resulting in an improved efficiency in oxygen usage [2].




References:


Wikipedia contributors, "Bohr effect," Wikipedia, The Free Encyclopedia, http://en.wikipedia.org/w/index.php?title=Bohr_effect&amp;oldid=618215597 (accessed August 4, 2014).
Chr. Bohr, K. Hasselbalch, and August Krogh. Concerning a Biologically Important Relationship - The Influence of the Carbon Dioxide Content of Blood on its Oxygen Binding. Available from http://www.udel.edu/chem/white/C342/Bohr%281904%29.html (accessed 04.08.2014)