I'm currently on my second playthrough so I kind of expect what should be going on, I just got done with the whole Tops incident and completed the quest with yes man. The NCR npc showed up to warn me like he should but there was nobody to show up on behalf of Caesar's Legion to give me Render Unto Caesar. The only difference I can think of why this would happen from my first play through and this one is, when I went to do the quest "Left my Heart" in cottonwood cove (which is the starting location for "Render Unto Caesar") I ended up killing a lot of Legion members in the area and finishing off by dropping the barrels of toxic waste from up on the cliff. This was said to kill all in the camp but I didn't stop to think it would affect me later on in the game with a major quest like "Render Unto Caesar". If this is the case I would say this wasn't thought out very well by the developers since it disables progression of other quests such as Arcade Gannon's companion quest which requires you to be on the said quest. So in the end this might not have to do with the radioactive barrels even though it makes the most sense but the point is if anyone knows how I could make a work around possibly through console commands? Maybe spawn the npc who delivers the quest, named Alerio. Or even one that could put the quest in my log, not completed obviously but just started?

You may have killed the boatman there when you did that... but I'd suggest still fast travelling to cottonwood cove to see if you have a means of getting to the fort. It may be intentional that, doing what you did, you are left without peaceful means of reaching the fort but it does seem bugged if you can't get there at all. You might have to swim there!

I was able to get Arcade's quest to trigger before ever going to the fort though so I think there are enough other triggering conversations for that one- but yeah I'm not sure how the global story progression variables come into play for it.

As far as console commands go, try:

setstage 00129D14 10

For arcade's sidequest (which can be annoying to get to trigger anyways) you can also try:

setstage 00157E60 10

The problem isn't reaching the fort though, I need that quest. Although if I can trigger Arcade Gannon's quest without it, then I could care less. According to this fallout wikia though it says that I need the quest to initiate the trigger.

http://fallout.wikia.com/wiki/For_Auld_Lang_Syne

Thanks for the console commands btw

Yeah those quests happen at the same story progression point (any one of them triggers the same global variable defining story progression to be set) but you do not need to have started ALL of them. It checks the global variable and not the individual quests, but yeah better safe than sorry. Also you may need to manually add the mark of Caesar!

player.additem 001374AE 1