The service standard for WT and WT+ is: Choices of wine should be offered during first bar service AND meal service! This also applies in CW but that service is much more complex.
As mentioned, there are certain crew that do a shortcut and only offers it during the bar service as it saves them time. I think it's ridicilious not to offer it during the meal service. I usually also ask them whether they like Bordeaux or Chardonnay and the passengers seem to enjoy that choice! Still, I once had a purser that said I shouldn't do that as it takes far too much time...