Which version(s) of SRP are in ISO/IEC 11770-4:2006?
The multiplier parameter $k$ is different between SRP 6 and 6a. You can see that RFC 5054 calculates it using a hash of the domain parameters (modulus $N$ and generator $g$), so it is using SRP 6a, as opposed to SRP 6 where $k$ is constant.

Likewise, in section 6.2.1 of IEC 11770-4 – the October 2005 draft at least – the equivalent value $c$ is defined as a hash of the domain parameters which it calls $q$ and $g_{q-1}$, so it too is based on SRP 6a.


  Also: ISO/IEC 11770-4:2006 can use an Elliptic Curve setting, with (I guess) shorter cryptograms; is that the case for SRP?


Yes. The protocol in 6.2 is defined for either of the fields in section 5: the discrete logarithm one or the elliptic curve one.