How long to list a coin? I sent a pull request last week, still no reply…
I am not sure how long does reviewing of pull request usually take, but my guess is that it isn’t long compared to time between releases.
New altcoins get introduced in new versions of the app that are usually apart in couple of months.
By then your pull request will likely be reviewed, if submitted correctly.
It will likely take about a month for a new release of Bisq, but there are no specific rules about that, so there are no guarantees.
And is there a way to know if the pull request was actually made? 
You can look it up on GitHub to see all of the pull requests or search for it in the repo.
but where exactly? I had a look but I’m not sure where I could see it