Most of the gay venues are around District 1, thought there is nothing in Saigon that's similar to Silom in Bangkok.
It depends on how long are you staying in Saigon for. if you 're staying for 2 weeks or longer, I would spend 1 week in District 1 and the other week in a neighborhood further away from the center, so you can experience both words.
If you're just staying for a week or so, then it depends what you want to get from the gay scene. if you just want to hang out, drink and enjoy the crowd then you can stay in district 10 and get a Grab to/from D.1. it's usually pretty cheap. However, if you also plan to go back at your place together with a local guy picked up in gay bar, then some of the guys might back off knowing there is a 30 minutes or ore drive involved, unless you let them spend the night at your place.
Not staying in the city center might be even a winning strategy when it comes to scoring guys through apps.
As most of the foreigners stay in district 1, you will attract more attention from the guys around, whereas if you have stayed in the center you would have to compete with a much higher number of foreigners for the same Viet twinks.