If Bill dies during High Times the quest can still be completed for partial XP, but Tapper will continue to charge for water at Freeside's water pump afterwards. If both Bill and Jacob Hoff die during High Times, the Courier will gain infamy with the Followers when the quest is turned in. This can sometimes happen accidentally if caught in the crossfire by Freeside thugs.
After helping Bill shake the addiction, the Courier can talk to Tapper and use the Freeside water pump for free.
When entering the Atomic Wrangler in the company of Arcade Gannon, Bill Ronte appears to slurr "Howdy Arcade", although this does not appear to lead to any new dialog options.
"Julie? Ah, I love Julie. She's such a nice lady. One time, I was working on the water pump and she came over, put her hand on my shoulder, and told me I was doing a great job. Great job she says! I just choked up and didn't say nothing. Compliments are so rare these days."