Personally, I can only smoke weed if I have some type of benzo. At least 2mg. Weed gives me massive panic which is odd since uppers do not.
For you, the weed and benzo will make a nice high. I'd say the extra relaxation will give you a spiritual buzz.
But as you already know, benzos are addictive, so if you start doing them everytime you blaze up, you're gonna build a dependence, unless you smoke less than 5 times a week.
What is your current tolerance to alprazolam? I can take upwards of 20 mg and be fine even though I rarely take them.