I have been studying these drugs for over a decade.

There are studies and clinical observations published that using a drug that alters a neurotransmitter in the brain, causes the brain to try to adjust things somehow (this is not well understood), and that affects others.

Here are some examples:
1) Some opiates (including tramadol), will affect serotonin levels (expression) as well as sitting on mu pain receptors.
Oxycodone is one synthetic that does this alot but others do too.
The "itching" they cause as a side effect is thought to be a serotonin release and not histamine effects.

2) Some neurotransmitters are stimulated by histamine in the brain. This cascade begins with histamine which acts like a trigger.
http://www.ncbi.nlm.nih.gov/pubmed/21713693

3) Long term use of SSRIs is thought to alter dopamine levels in the brain as a consequence. The reverse may also be true... using a dopamine based antidepressant like Wellbutrin, may reduce serotonin over time. (or affect its expression).
People on long term SSRI therapy may develop a syndrome similar to Parkinson's....or tardive ..where the legs twitch and facial, tongue and neck muscles twitch involuntarily. Not everyone gets this but about 10-15% or so do.

4) Here is a link...complex but maybe helpful for you from Dr. Kraslow:
http://www.drkaslow.com/html/neurotr...repletion.html

There are sites on the web explaining Wellbutrin/Zyban irritability side effects:
Just Google "Wellbutrin agitation", and you will find many discussions.

So it might be that RAISING your Wellbutrin is not the answer for you. Be very vigilant about side effects of this. Many doctors just automatically raise doses when patients complain... and for many this is not really a solution.

We really don't know if dopamine is a triggering neurotransmitter for some serotonergic responses. However reputable medical sites like WebMD where interactions are listed do not give Wellbutrin as a problem with tryptophan:
http://www.webmd.com/vitamins-supple...t_interactions

One solution for you long term may be SAMe. This supplement naturally offers stimulation and support to all neurotransmitters, and also liver metabolism support and joint/ligament repair.
It is slow onset, but very helpful to some people.

So the bottom line is: You may become more tetchy on higher doses of Wellbutrin. As the doses are raised you may have cardiac palpitations, which can be alarming...so watch for that.
Your new blood pressure medication might suppress this side effect for a while, so it might take time to manifest, if it is going to.

If tryptophan is too slow for you to give the results you want, you may try 5-HTP... 50 or 100mg at bedtime. Some people like this...it is made from tryptophan, and is really a pro-drug...a supplement with drug-like speed of onset. It is over the counter.
I personally didn't like it when I tried it during my menopause for sleeping problems...my solution was B12. But people do vary, and I've met them, mostly women who like 5-HTP.