switch is actually a d/s term and so definitely relevant regardless of the sex of the couple, but i know most people mean vers when they use it.

anyway, they're definitely relevant but i feel more flexible than with gay men!

with gay men it's pretty exclusively about penetration preference, and it definitely can and does mean this for lesbians too (especially i.e. stone tops!). but i think because of the nature of lesbian sex not being focused on penetration, it also is more likely to include a broader "likes giving/leading" vs "likes receiving/being led" implication (which isn't necessarily the same as dominant/submissive).

SO BASICALLY--the short answer is yes it's absolutely a thing, and anyone who says otherwise is either clueless or morally opposed to women actually fucking, but the exact usage of it can differ somewhat sometimes!