Are Terms of Trade reciprocal?
Terms of trade is a measure of relative prices, and prices only. There are no quantities involved. As a recent review paper puts it:

"with exceptions that I will note below, most trade economists have defined a country’s terms of trade as the price of its exports divided by the price of 
its imports, $p_X/p_M$" (p.2). 

Therefore, by definition, in a two country model, they are reciprocal. In a model with more countries, there can be differences, as some countries could import or export different goods. 

Actually, I don't know which Wikipedia you are looking at, but in the English version, the first line states:

"Terms of trade (TOT) refers to the relative price of exports in terms of imports and is defined as the ratio of export prices to import prices."



For future reference, Wikipedia is an unreliable source. If you are in an educational institution, it is likely you have access to the New Palgrave Dictionary of Economics (the terms of trade article is here). If not, you can google "terms of trade pdf" and hopefully get the slides of a generous professor who is sharing his/her knowledge with the world.