Well, ODBC in general is outdated / semi-retired (for about 10 years, in case you wonder) and replaced b a faster / more easy to handle technology clled OleDb.
That said, forget it - go for a TDS implementation and be happy with it.
iOBDC is an ODBC Driver Manager and not an actual ODBC Driver, so if you were to use it an ODBC Driver would also be required for MS SQL Server. If you are developing on Mac OS X and have a cross compiler for Windows then you can make an ODBC application to perform these database operations you require on Mac OS X and then cross compile for Windows. The beauty of building an ODBC application is that all you then need to is source and ODBC driver for your target database and operating system, such that you are not looked into either. OpenLink Software for example have a suite of ODBC drivers for most popular relational databases including SQL Server, as detailed at http://uda.openlinksw.com/sqlserver-odbc/
With regards to OLEDB, it might be a newer technology that ODBC, but has failed the test of time as it is Windows specific and has since been superseded by ADO.Net another Windows specific technology (unless you have Mono). Whereas ODBC is a major generic data access API available across most commercial OS'es Windows, Linux/Unix, Mac OS X etc. and continues to be supported and maintained by other third party vendors like OpenLink Software who will ensure it remains a robust and viable cross platform and database independent API.