Does a wireless +7db antenna also affect transmit?

My apologies I am new at this. I frequently like to stay at bed & breakfasts and purchased a laptop with a built-in wireless card. Found out the b&b's that have wireless often mean you get wireless reception in the common area while your room is out of range.

So, I searched how to extend my reception and came across an Orinoco kit (laptop card & +7db external antenna) to increase my reception. I'm used to antenna's only affecting my reception, does that +7db antenna also affect my transmit? I'm just thinking what good is that kit if I can receive better but still need to be in the common room to be able to visit sites.

Thank you