Is there a way I can put a wildcard in this file? For example if I want to accept any connections from say "all.me.net.nz" Is this how I should enter it :
ALL:ALL@ME.NET.NZ:ALLOW

IF not then what is the syntax?

I've not used this much, but believe you can accomplish what you want by specifying the IP address

ALL: 123.45.67.890

Adding something like :ALLOW would be redundant since you're editing the HOSTS.ALLOW file; that's if it even worked....

Id like to add you can use hosts/netmasks and separate them with comma's as well for more fine-grained control:
example0: 110.1.0.0/16
example1: 110.1.24.0/24, 110.1.25.0/24, 254.1.2.132/32
or:
example2: ALL EXCEPT 127.0.0.1, 200.210.0.0/16

As a final note Id like to say this doesn't work automagically, the app has to be compiled with TCP-Wrappers support (like ./configure --with-libwrap) to take advantage of this.

Yes wildcards will work in TCP wrappers using the follow implementation.

The access control language implements the following patterns:

A string that begins with a `.´ character.
A host name is matched if the last components of its name match the specified pattern.
For example, the pattern `.tue.nl´ matches the host name `wzv.win.tue.nl´.

A string that ends with a `.´ character.
A host address is matched if its first numeric fields match the given string.
For example, the pattern `131.155.´ matches the address of (almost) every host on the Eindhoven University network (131.155.x.x).

Check out man hosts.deny for more info..

/Raz