Hi, yes the orientation of Antenna may hamper the transmission, not to much extent.
When I did experiment, I kept it perpendicular at both ends, with the antenna still kept in coiled form and was able to attain an outdoor Line of Sight range of ~115m which is nearly equal to the Max. range of RFBee.
I used the Max. Tx Power ATPA7 (10 dBm) and Min. Frequency 4.8 Kbps ATCF5.
Thanks