Today I came across two pre-1900's bottles that were sadly broken. I'm just trying to find out how old they are, to determine if it's worth going back again and trying to find some intact ones. I don't generally know a lot about bottles from this era.
Are you sure they're pontils? They look like pretty standard European champagne bottles. Hard to date but if they do have pontils then they could date to the 1870s or before. They aren't something that I'd specifically seek out unless there's something about them that's more special than the photo lets on, but there could be something else there worth looking for.
Maybe that is simply what they are. I didn't see anything particularly special about them. I find lots of pieces here that look interesting, but I think that most have been destroyed by excavation for a pipeline that was put in years ago.
They're likely a similar era to your Coke bottle then. Since these were made in Europe they used older techniques longer into the 20th century than you'll find from the States, but they still look old enough to be worthy of further investigation. And if you found a straight-side Coke there then the area definitely has some serious potential.