By 'polished flat pontil' I assume you mean a polished flat base?
I don't know who made this piece, but it has a curious similarity to WF, the quality looks similar anyway. It is NOT a piece I recognise from them, but the colour looks similar to full lead crystal WF and the rim looks similar to WF pieces.
Hopefully Emmi will be able to help more. If she misses this, then stick it on wf.com to check with the experts.
A better pic of the base would be helpful...the lower half of the vase, and the underneath.