Yep! All tickets on Project Admission that are part of the same listing are adjacent to each other, unless otherwise stated in the Seller's notes, which you can learn more about by clicking here.
Some venues may number their seats using odd and even numbers, making it appear that your seats aren't next to one another. No need to worry, your seats will be next to each other even if the numbers aren't.
Other venues may have General Admission (GA) seating or standing. Tickets to general admission events may have a ticket number assigned to them, but it's common for these events to be standing or sitting room only.