I can't say whether the same applies to a lap infant or not, but as long as there is a ticket for the correct name, you should be fine. It could always be that the other infant just doesn't travel, for example. I'd attempt to check in online, and if that fails then check in at the airport. Tbh, I wouldn't bring up the issue unless they say something about it, and then too just say that it is odd they see the wrong name as well, even though you already had VS correct it.

That said, ticketing systems between airlines can be slow to update. So it could be that in a few hours the phantom ticket will disappear.