Thanks for the replies.
I varnished 24 hours after the second coat of epoxy. I rubbed down and wiped with acetone.
Here is the reply from Epifanes:
We typically recommend waiting 10 days (It takes that long for epoxy to cure and for the production of blush to stop). Depends on drying conditions of course. Once sanded, the epoxy should be washed with acetone, ammonia, or vinegar. Finally, a warm soapy water wash.
When asked about waiting longer, here is their other reply (I mentioned using Cobtalt drier):
It might still dry. There is cobalt drier in varnish currently. Adding more will produce a less flexible (won't last as long) finish.Honestly, remove the varnish (likely it will come off with solvent) clean off the blush and recoat.
So I've decided to wait 10 days and do what they say. Rather a lengthy process but the Epifanes finish is great. I wish I had removed the bubbles using a hot air gun though. I suppose I can rub them down. I'm only making a toilet enclosure, so the finish isn't crucial.