When truing a wheel, is it enough to only use a tension meter, and not a truing stand? I presume that if you get all spoke tensions equal, and at the recommended tension for the spoke thickness, then the wheel will be true. 
My intention is to get a wheel reasonably true (laterally) by seeing where it rubs against the break blocks in situ, and then use the tension meter to fine tune it. Just means I don't have to purchase an expensive stand to measure that the hub is centred, or the rim is over the centre of the axyl. Are these last two measurements unecessary if the tensions are equal?
A wheel could theoretically be trued by tension alone if you started with a perfectly manufactured rim, hub, spokes and nipples and you were building a perfectly symmetric wheel.   The reality is that there are minute differences and that tolerances are not all that tight.  Not to mention that ultimately the wheel has to go into a frame that also may not be perfect (dishing).

The short answer is no.  I've had many sets of hand built wheels that were beautifully crafted and never saw a tension meter because the tension was hand checked.  But, they were built in a truing stand and were incredibly close to perfect.  Your initial presumption is incorrect.