I’m on an alliance of 1, and so, in fighting wars, I’m also faced against other alliances of one or alliances with more than one player but only one that participates in wars. As such, if I were to defeat the other team during the very first match, I would expect to receive 1500 points, which would be comprised of 1000 for “current available points” and 500 for “bonus points for victory”. However, for the war that is currently ongoing (as of writing this post), for the very first match, even though I entirely defeated the other team/alliance, causing a reset, my alliance only received 1495 points for the win. For the next two matches, which I also won, my alliance received the expected 1500 points per match. This can be seen in the screenshot below:
I recall that the opposing player was on-line at the time of the first battle. Perhaps this player was in the process of leveling up one or more troops used on the war team at the same time or adding emblem levels at the same time (all heroes on the opposing team were at 4-80 when I started), and that perhaps explains the discrepancy? Even if that were the case, I think this is a bug regardless.