Again...try it both ways.
I really don't think it's a question of reverb on top snare insert VS snare bus.
It's more a question of the reverb type/size/decay and how you dial it in...plus how it all sits relative to the rest of the track.
That said...
Since you're talking about a "top mic"...I assume you also have a bottom mic.
OK....but IMO, I would treat the whole snare as the snare. IOW, the combination of both top and bottom mics...and then treat that with the reverb, rather than dividing up the snare and putting reverb on top but not on bottom...but again, it's so easy to try it both ways and see what you like.
Also...don't just put it on the snare. You might be better off creating a drum bus...and then just putting the most of the reverb on the snare, but don't leave the rest of the kick completely dry....it will sound weird...but again, try it and see what you like best.
I usually run my entire kit out to a plate reverb using an Aux bus, and then add how much reverb I want per drum element, with the snare usually getting the lion's share...but I always add some to the rest of the kit elements too, so that the whole kit sounds like it's in the same space.