userbouquet.favourites.tv is a system bouquet (this is is the one you add to favourites by remote). Although linux will see this as different to your one (Userbouquet.favourites.tv), I would suggest you change the name to something else. Perhaps "userbouquet.dfoxfav01.tv"
Option 1
There is a facility in images that allow for unlinked bouquets. You can send any bouquet file there and it will be presented to you. On OpenVix we default this to off. This will come at the top of the list and alter all subsequent numbers.
Transfer your .tv file to /etc/enigma2/,
Enable unlinked bouquets in the customise or channel list context menu.
Restart
Option 2
Stop enigma2 with "init 4",
Transfer your .tv file to /etc/enigma2/,
Edit bouquets.tv, add the following line to your chosen location, #SERVICE 1:7:1:0:0:0:0:0:0:0:FROM BOUQUET "userbouquet.dfoxfav01.tv" ORDER BY bouquet
Save and ensure transfer completes
Restart receiver
Option 3.
Use a channel editor like dreamset/e-channelizer to import then add your bouquet.