If you have any concerns as to whether a material you've used on a painting might smear when you apply varnish, treat the painting to a light coat of spray varnish first. Allow this to dry thoroughly before applying more varnish with a brush. Or, you could skip the brush on varnish completely, and simply build up a couple more layers of spray varnish. (When varnish is brushed on textural surfaces it creates unattractive bubbles which can mar the work's appearance. Textural paintings are best treated with spray varnish only.)
If you choose to use both types of varnish on the piece, make sure they're compatible with one another. Check the manufacturer's web sites for guidelines, or call their information hotlines if you're not sure.