If both paint and varnish are oil-based (brushes clean up with mineral spirits) you ought to be fine putting varnish over paint.

Only caveat might be if the colors you used for your boat's name are fairly light in value you may see some yellowing over time & exposure. This is the varnish doing part of what it's intended for: the yellowing is from UV inhibitors in the varnish's formulation acting as a UV filter, exactly why it's necessary, to protect the epoxy underneath.

Later on when it comes time to revarnish you may want to remove the old painted name then refresh.

Had I been doing this I'd have reversed things - paint over varnish instead... my $0.02 for what it's worth....

Very Helpful Thanks for that advice I’ll probably leave it for now, Varnish over paint and refresh in the future. 😎