I have rams and ponds in a 2.5g with wisteria and other plants, and they don't eat the plants. They do eat the dying plant matter though. But it may depend on the species of ramshorns you have, as one species does eat healthy plants, but they're not as common.
But don't worry, you won't have any trouble. I had a plant tank that I put absolutely no food in for 3 months, and I'm still pulling dozens of pond snails out of the tank. Once they get going they're hard to stop, even with total neglect.
I just want my planted tanks to be perfect. Is that so much to ask?
55g: (Mostly) African riverine species: Alestes Chaperi, breeding pair of Kribs, and rhino pleco
30g: Newly established reef tank
10g: Planted but fishless
5g: Unplanted with various snail species
2.5g: Heavily planted with betta.