Is it possible to see how many bounties offered a specific user and how many of these bounties were awarded?
For any user, you can go to their profile and under activity you can choose the bounties tab. One of the things you can see there is the list of offered bounties.
If you want to see how many bounties were actually awarded, I do not know about such possibility displayed directly on the site. But you can use SEDE to get this (and various other things about bounties). When using SEDE, keep in mind that it is only updated once a week.
- You can get the questions where a specific user offered a bounty: Questions where I offered a bounty .
- You can get the answers where a specific user awarded a bounty: Answers that received bounties from me. (Although getting the bounties awarded by some user is a bit tricky - see this conversation in the SEDE chatroom.)
- As a complement: Bounties from me awarded to no answer
Considering my limited experience with SQL, you should take the above queries with a grain of salt. (But since I consulted them with a more experienced user in the SEDE chatroom, I suppose they should be fine.)