You bid by seniority, even for long call and short call. Generally speaking, long call goes more senior, and there are far fewer long call lines than short call. Round 2 of bidding includes build up lines (the extra flying left over after round 1), long call, and short call lines. So you bid for all 3 of those at once and it just goes by seniority.

I can't speak for other bases, but TYS usually only has 2 or 3 long call lines. According to the contract, there has to be a long call line for every percentage of short call lines. So they keep it minimal.