Was it the Bowen lab results themselves that told you that it wasn't in your red/white blood cells or was it a doctor that told you? I find that statement confusing from what I know.
Perhaps when they took a look at your blood they found Lyme in locations other than the actual cells mentioned. The Lyme spirochete can burrow through tissues and can be found in other places besides in the cells themsleves. Since they are pleomorphic, they can be in several places in your body at once and even if they're not in your WBC's or red blood cells, if they are in other locations then you have Lyme. They could just be swimming around freely in your blood, too.
Bowen should have sent your doctor a digital photograph also - have you gotten this yet and does it show anything? Also did you test positive for the co-infections they test for (babesia and erlichia)?
I am going in in a few hours, ironically, to have my blood drawn for the Bowen test. For their accuracy, from what I have read they are the best around. This is because they test for the actual presence of the Lyme antigen rather than other tests like the Elisa that test for only the antibodies which not everyone produces when they're sick.
I also know that they have had 2 other labs verify their work and the results agreed 100 percent. I say any lab that actually uses darkfield microscopy and takes and actual pictures of the little buggers in our body is OK by me! :)