隻給我報銷在國內的機票, since the travel exp. in 國內 is for business purpose;
不給報銷回國的機票, since u were on vacation,來回中國的機票 exp. were for personal travel intention.
Think this way, if there was no such things of "拜見客戶", you at least pay the 來回中國的機票 exp by yourself.