Translation:All of the buildings are made of concrete in this city.
TLD states, -Daq "indicates something is happening (or has happened...) in the vicinity of the noun to which it is attached."
To me, this seems like vengvamDaq applies to the verb. And in this case, the verb is consist. So, it seems to me like the sentence is describing where they were consisted, which doesn't make sense to me.
For example. My (admittedly limited) understanding is that vengvamDaq qagh vISop means that we know nothing about where the gagh was from, but that the eating must take place (or have taken place...) in the city. Is that correct?"
And if I'm correct about where the eating takes place, how does that jive with the verb consist above?
Theoretically this sentence could imply that if the buildings moved they might consist of something else there. That's clearly absurd as the buildings are unlikely to move and unlikely to change their constitution. So it makes much more sense to just read this as a comment on which buildings we are talking about.
I see where you're coming from. You could avoid this by saying tungyen luyugh Hoch vengvam qachmey.
However, I'm not sure the original is wrong. You seem to be imagining yugh to mean some kind of "they put it together" verb. All the verb means is these buildings are made of concrete, and this being-made-of is the case in the city.
Consisting of concrete is happening in the city.
In Klingon, unlike in English, states of being are also actions.
vengvamDaq jIQuch I am happy in this city.
vengvamDaq law' qachmey The buildings are many in this city, there are many buildings in this city
vengvamDaq tungyen yugh qachmey The buildings consist of concrete in this city.