I wouldn't be so sure about LH buying TAP. The current CEO is far less acquisitive than the previous one. It has been badly scarred by the bmi fiasco and still has to fix Austrian and it's in the midst of a very radical overhaul of its own internal structure.
As for IAG, I think another acquisition in the current year would be unpalatable for investors.
It's also worth noting at this stage it's not known whether the whole of TAP will be sold off, or just a stake in the airline, which will influence potential buyers significantly IMHO.