It seems very clear that people with three dots on their left shoulder are part of the secret group "tyger tyger". And this makes BERTRAM,SMITH AND MCALLISTER amongst the members of this group or, if you like, Red John's allies. This is why they are seen many a time together.I have a strong hunch that only Red John's followers wear this TATTOO. Red John himself does not have this tattoo and this makes STILES and HAFFNER amongst strong contenders.
From the philosophical aspects of William Blake's work, however, only Brett Stiles seems to be the person who could understand, scheme and design an evil group  based on FEARFUL SYMMETRY. Also, Bruno Heller himself said that Red John is not a loner frustrated killer, rather he is like a schemer who might design the scheme but might not do the dirt work himself. Does not a person as intelligent, smart, charming and persuasive as Stiles fit this description perfectly?