The issue isn't so much a Speaker's warrant as an order of the House. A Speaker's warrant is issued pursuant to an order of the House, and I believe it's sound law to say that an order of the House has the standing of an order of the Superior Court. It would have equal standing with, if not priority over, the order of any court affecting Mr. Schreiber.
Currently, there is no order of a court affecting Mr. Schreiber. We're now under an order of surrender.
I would take the view that, yes, the jailers—if I want to use that term, and it's not a very nice term—or the persons responsible for keeping Mr. Schreiber in custody would be obliged to respect the Speaker's warrant pursuant to a House order. Failing to do so would be potentially, or could be taken as, a contempt of Parliament by those responsible officials.