It’s hard to set a number to the rewards, as they depend on corp size, attacker size, activity levels etc.
To give some idea, the Reputation & Reliability system: ‘Reliability’ bonuses of up to 8% (4% Personal, 4% Corp) on Standings, Mining, Evermarks, and as a discount on NPC POCO taxes whenever you are in a player corp.
‘Reputation’ bonuses of up to 8% (4% Personal, 4% Corp) on ISK and LP earnings are available when you’re in a war-eligible player corp. If the corp becomes engaged in a war, 50% bonus are applied to both, so up to 12% bonus earnings in all the above areas.
I was asked in-game ‘Why split R&R into Personal/Corp’. This was done so the Corp has a permanent portion to manage, even if players come and go. Which can help (or hinder) with recruiting. But it’s the members who actually earn those points, so they get their own to take with them if they move corps.
As for War rewards, that will depend entirely on the size and activity of the corps involved. Let’s pick an example: Your 8-man corp is 'decced by an 80-person corp. Your war bond is 66 million. Their war bond is 210 million. Your corp of 8 completes 16 points of War Action missions, for a per-capita total of 2.0. Their corp of 80 kills 10 of your ships, but those ships and their interdicted tasks were only worth 60 points total, for a per-capita score of 0.75.
Winner: You. Payout: (2.0 / (2.0 + 0.75)) * 210 Million ISK = 152.7 Million ISK to you.
Now if you completed only 7 War Action points, but held losses down to only 1 Destroyer (2 points) and 1 task (1 point), then your per-capita is 0.875 and theirs is 0.0375 :
Winner: You. Payout: ( 0.875 / (0.875 + 0.0375)) * 210 Million ISK = 201.4 Million ISK to you.
So the key will be completing War Action tasks with as few losses as possible. On the other hand, it will get more defender ships out in space doing things, which gives the attacker more targets. So more activity and likely more destruction; where being skilled at what you do counts for more than being the guy with 10x as many ships.